Welcome to today's Pinterest fourth quarter earnings conference call. My name is Jordan, and I'll be coordinating your call today. If you'd like to register a question, you may do so by pressing star followed by one on your telephone keypad. I'm now gonna hand over to Neil Doshi, Head of Investor Relations to begin. Neil, please go ahead.
Thank you, Jordan. Good afternoon, and thank you for joining us. Welcome to Pinterest's earnings call for the fourth quarter and full year ending December 31, 2021. I'm Neil Doshi, Head of Investor Relations for Pinterest. Joining me today on the call are Ben Silbermann, Pinterest President and CEO, and Todd Morgenfeld, our Chief Financial Officer and Head of Business Operations. Now I'll cover the safe harbor. Some of the statements that we make today regarding our performance, operation and outlook, including the impact of the COVID-19 pandemic, may be considered forward-looking, and such statements involve a number of risks and uncertainties that could cause actual results to differ materially. In addition, our results, trends and outlook for Q1 2022 and beyond are preliminary and are not an indication of future performance.
We're making these forward-looking statements based on information available to us as of today, and we disclaim any duty to update them later unless required by law. For more information, please refer to the risk factors discussed in our most recent Form 10-Q and Form 10-K filed with the SEC and available on the investor relations section of our website. During this call, we will present both GAAP and non-GAAP financial measures. A reconciliation of non-GAAP to GAAP measures is included in today's earnings press release and letter to shareholders, which are distributed and available to the public through our investor relations website located at investor.pinterest.com. Now I'll turn the call over to Ben.
Thanks, Neil, and hi, everyone. Thank you for joining the call. 2021 was an important year for Pinterest. We remain laser-focused on helping everyone get inspiration for their lives and building a dedicated space online to plan and create their futures. We believe that the demand for a positive place to plan your future will only continue to grow over the long term. That's why we spent the past year investing heavily in evolving how we inspire pinners by building a new publishing platform for creators. We believe that when we connect pinners, not just with great ideas, but also with the great creators behind them in rich new formats like short form video, the overall experience is more inspirational. When people are more inspired, they do more planning and shopping.
Advertisers are able to reach consumers with more intent, and that in turn drives more value for Pinterest. In 2021, we made our publishing tools available in 37 markets and launched 150 new features, many of which were released in October, so it's still very early, but we're already seeing signs of promise, specifically a rise in session frequency and time spent from people who followed multiple creators. This supports our hypothesis that our investments in native content can be engagement accretive over time. We believe that with sustained investment, we'll see these trends grow as more and more pinners find and follow creators they love. We know we're building this new platform in a challenging environment. In Q4, we saw monthly active users decrease 6% year-over-year to 431 million.
This was primarily due to the continued unwinding of the pandemic, lower traffic coming from search and increasing competition for user attention. We're clear-eyed about these recent headwinds, and we believe that over the long term, our new publishing platform will deepen engagement by pinners. We're also continuing to improve the core experience to help surface the most relevant content at the right time. With shopping, we're building a more dedicated experience to help people discover and buy what they love, as well as expanding our tests of seamless checkout. We're also working to improve the advertiser experience, helping them optimize their budgets and more effectively measure performance with the changing privacy landscape. We're working to build on the business milestones we achieved in 2021, where we surpassed $2 billion in revenue for the year, growing revenue 52% over the previous year.
We also posted our first full year of GAAP profitability. Our aspiration is to build an end-to-end platform that gives people great inspiration and the tools to buy, to make, and to do those ideas for their lives, all in a space that's both positive and encouraging. We believe that the world needs this, and that's why we're increasing our investment to build it, and I'm confident that our team is up to the task. Now I'll turn it over to Todd, who will share more.
Thanks, Ben. I'll share some further details on the trends that we saw in the fourth quarter and provide a preliminary outlook for the first quarter of 2022. We were pleased with the financial results that we delivered in the fourth quarter. Revenue grew 20% year-over-year to $847 million with an adjusted EBITDA margin of 41%. While most of the details about our financial performance are in our shareholder letter, I'd like to provide some additional color. Strength in the quarter came from large retailers, mid-sized and managed small advertisers, and international markets. This was offset by muted demand from CPG advertisers who continued to face pressure from supply chain issues.
Furthermore, with the continued distribution and placement of Idea Pins during the quarter, we estimate that the negative impact to our fourth quarter year-over-year revenue growth was in the mid-single digits, similar to the third quarter. This impact was factored into our guidance for the fourth quarter. I wanted to take a couple of minutes to discuss fourth quarter engagement, particularly in the U.S. Our U.S. monthly active users declined 12% year-over-year to 86 million, primarily due to pandemic easing relative to the year ago quarter. We also believe that time spent on competing video app platforms contributed to the year-over-year declines. Furthermore, our monthly active users were negatively impacted from lower search traffic due to Google's November algorithm updates. In fact, more than half of the Q3 to Q4 sequential decline in U.S. monthly active users was attributable to Google's algorithm updates starting in mid-November.
We're examining the overall impact from recent search algorithm changes as it appears to be more persistent than we've seen historically. Our teams are working diligently to understand this, but it may take some time. Looking at users by platform, U.S. monthly active users coming to Pinterest from the web, desktop and mobile web, declined around 30% year-over-year, while U.S. monthly active users coming to Pinterest from mobile apps, who account for a significant majority of our impressions and our revenue, declined around 6% year-over-year. We're taking a number of steps to increase engagement on Pinterest. First, we're investing in native video content in a creator-led content ecosystem. In the long run, we believe that this can be engagement and revenue accretive. As Ben mentioned, the early data make us cautiously optimistic.
Bending the curve on overall engagement will require us to scale this effort with sustained execution over several quarters. In the near term, we plan to invest in our core discovery and planning engines to provide our users with a richer, even more personalized experience across our various surfaces. We plan to apply more data and larger models to our sophisticated machine learning stack to help with content recommendations, home feed personalization, and an improved search experience for existing, previous, and new users who come to Pinterest. Turning to our preliminary outlook for Q1. In my remarks last quarter, I noted that engagement trends on Pinterest had not yet returned to pre-pandemic norms, specifically to the mix of at home versus out of home use cases that we saw in 2019. In Q4, these trends began to normalize.
For example, the propensity of pinners to adopt use cases like home decor or cooking in the fourth quarter of 2021 was similar to what we saw in the fourth quarter of 2019. As we revert to our pre-pandemic use case mix, we expect that the pandemic unwind will be a less meaningful engagement headwind as we move through 2022, particularly after mid-March, when we will lap the widespread easing of lockdown restrictions. That said, engagement headwinds from search algorithm changes and from time spent on competing platforms are more persistent and could potentially disrupt our normal seasonal trends. Given this context, we think it's most helpful to tell you what we know today. As of Tuesday, February 1st, U.S. monthly active users were approximately 86.6 million, and global monthly active users were approximately 436.8 million.
On the revenue side, we expect Q1 revenue to grow in the high teens on a percentage basis year-over-year. Please note that our Q1 revenue guide takes into account a few considerations. First, the macro environment remains challenging for our CPG advertisers who are still dealing with supply chain and other macroeconomic issues. We believe this headwind could persist for a few quarters. Second, we continue to monitor the impact that higher CPAs could have on our more price-sensitive advertisers. There are some exogenous factors that appear to be resulting in higher CPAs, including overall demand for digital ads from advertisers. On Pinterest specifically, if engagement declines continue, we could eventually expect to see some constraints on our monetizable supply and in turn, higher CPAs. This supply constraint is not something that we're seeing today, but we're monitoring it carefully.
At the same time, we're investing in a number of opportunities to monetize our existing supply and to help advertisers achieve their goals. Third, our investment in Idea Pins and native video content will likely be a modest headwind to revenue in future quarters as it was in Q4. However, we believe that Idea Pins will be both engagement and revenue accretive over time. Finally, I want to touch on expenses. non-GAAP operating expenses in the fourth quarter grew 27% year-over-year. This year, we plan to accelerate our investments in the business in accordance with our key strategic priorities of inspiring content, shopping, our pinner experience, and advertiser success.
We expect our first quarter non-GAAP operating expenses to grow around 10% quarter-over-quarter sequentially as we continue to scale our investments in our native content ecosystem, our core pinner experience, and headcount across research and development and sales and marketing. For the full year, we expect non-GAAP operating expenses to grow around 40% year-over-year. The sequencing of that spend may change from quarter to quarter, but we'd suggest you look at the quarterly growth cadence in 2021 as a likely template.
Thank you to our teams at Pinterest, our advertising partners, our creators, and all the people that come to Pinterest to find inspiration. With that, we can open it up for questions.
Thank you. As a reminder, if you'd like to register a question, please press star followed by one on your telephone keypad. If you change your mind, please press star followed by two, and please ensure you're unmuted when speaking. Our first question comes from Ross Sandler of Barclays. Ross, the line is yours.
Hey, Ben, there's not really a nice way to ask this, so I'll just kind of ask it anyway. There's been some recent press reports that pointed to a number of senior executives leaving the company recently. Can you just comment on, you know, what's going on with that? Is that not accurate? And you know, how you feel about the senior management ranks as we look at your agenda in 2022. Then you guys said that the Watch tab is one of the fastest-growing products in history. Any way to just put some numbers around how big this could be in 2022? Is it still a little too early or, you know, are you expecting this to be a needle mover in terms of engagement? Thanks a lot.
Sure, Ross. I'll take your two questions in turn. You know, first of all, taking a step back, you know, a lot of people are coming out of the pandemic and they're reassessing their careers. Along with many companies, we see what some people are calling a great employee reshuffle. Based on conversations with some of our peers, we believe that our attrition rate is roughly in line with others. I'd also remind everyone that we've been hiring pretty aggressively. We grew our headcount by 27% over the last year. Tech press has covered some recent departures. You know, many of the folks in articles that were named are people that joined pre-IPO several years ago. They joined a relatively small private company. They made an incredible contribution.
I'm grateful for what they've done, and I'm excited for a lot of them to take their next step in bigger roles at smaller companies or in some cases, changing industries entirely. I'd also say that we just have an amazing bench of talent here at Pinterest, and this provides our existing employees a chance to take on more responsibility and to step into new leadership roles, which we're just thrilled about. Finally, we've been able to welcome some great senior talents in new areas where we're making investments, including shopping and content. That's kind of the story there. Your second question is about the Watch tab.
What I'd say is that we're not breaking out engagement by surface just yet, but we're really optimistic, even though it's early days on the creator effort in general, and in the Watch tab specifically. You know, I would just remind folks, you know, why we're making the investment and why we're excited about it. The first reason we're making an investment really comes down to the core value proposition on Pinterest, which is to provide inspiration. We think short-form video and connecting people with real creators is just an enormous opportunity to advance that vision in new ways.
Short-form video is being adopted all over the industry, but to date, what we see from most of our competitors is that the innovation on short-form video has been focused on entertainment, while Pinterest is more focused on providing inspiring and useful experiences that can help people get ideas and then actually realize them by making, by buying or by doing something in real life. The second reason that we're excited is we think that over time, the creator's effort can increase both time spent on the platform, but also the frequency with which people visit. You know, people often come to Pinterest when something's going on in their life. They might wanna remodel their home, they might wanna take on a new life project or plan a trip, and that's fantastic, but the engagement tends to be more periodic.
If you look at a lot of the largest platforms in the world, they're either social networks with a strong messaging component which pulls you back, or they have some sort of publish-subscribe mechanism between creators and their audiences. Up until late last year, Pinterest had neither. It was really buoyed by the utility of the platform. We think by connecting people to inspiring creators who can share their passions and their ideas every day, over the long term, that can shift. We're in really early days, but we're excited about both improving the core experience for users and the net impacts it'll have on the business.
Operator, next question.
Our next question comes from Eric Sheridan of Goldman Sachs. Eric, the line is yours.
Thank you so much for taking the question. Maybe two, if I can. You know, as we exit 2021, I'd love to look back and reflect on some of the learnings you had from some of the international expansion efforts, both on the investment side and building out versus what you've seen as monetization has started to come through in some of those international markets. In the release, you talked a little bit about some of the markets you're expanding into in 2022. Can we again frame it in terms of, like, what some of those investments might be versus what you see as some of the market opportunities, especially in a market the size of Japan? Thanks.
Yeah. Thanks, Eric. It's a great question because we're obviously one of the biggest growth drivers and clearest opportunities for us to continue the momentum we've had with our great traction with revenue performance is through international markets. I think. It starts with building a great team. We have some tremendous country leaders. We have some great sales leadership, and I'm really excited about the folks that we've brought on board. We've had a lot of hiring over the last year, and we've just done a great job of bringing the right people into Pinterest with the right leadership team. So that's one. More broadly, we, you know, we often get the question, why weren't we monetizing internationally quicker? Part of the reason was we wanted to get the user experience and the advertising experience right, both for our
Pinners and to make sure we are delivering great results to our advertisers when we started to monetize internationally. That's what we've done. We've proven that our full funnel advertising platform works in the U.S. We've built the right ad tech stack against that. We have the right go-to-market model and the right coverage model that we've built out in the U.S. What we've been able to do internationally is start to replicate the same trends. There's a lot of learning and a lot of it, you know, education and sales that needs to happen because of the nature of this platform. What we found and you know, you've asked questions in the past about which kinds of advertisers find success on Pinterest.
What we've learned is that those that value being on an inspiration-driven platform, one that is brand safe, advertisers that value unique insights into the commercial mindset of users long before they buy something, and who are open, therefore, to longer attribution windows, those are the advertisers that find success. We're seeing that same playbook, which takes a little longer to unfold, to build those relationships, generate that kind of understanding in the advertising community, but when it pays off, it's paying off with, you know, great traction and great growth in those markets that we've opened, most notably in Western Europe. You asked the question about 2022. In terms of growth, we're opening up in a couple more countries in Latin America. Colombia, Chile, and Argentina will open this year, so extending the reach within Latin America.
As you mentioned, we're really excited to start monetizing in a very deep ad market in APAC and in Japan. All of that work is on track, and I would expect us to continue to see some contribution from those markets by the end of this year. It takes time. You know, reflecting on your question, we opened Latin America last year, and while we've seen some early contribution, we've got a long way to go, and I think that's exciting for the future growth potential of the company.
Great. Thanks for the color, Ben.
Operator, next question.
Our next question comes from Mark Mahaney of Evercore ISI. Mark, please go ahead.
Okay, thanks. I'll just ask about MAUs or the monthly active users. I know you've talked about this a little bit before, but just please double-click on it. What's gonna cause North American, you know, MAUs to stabilize and then to start growing again? Like, what series of steps are you gonna be looking for in order to gain conviction that you'll be able to get back to kind of that reasonable growth you had, you know, pre-COVID and then the COVID rise and fall? Thanks.
Yeah, Mark, I don't know if I'm happy to start, and then Ben can weigh in a little bit on the product work that we're doing. I think the short answer to your question is we're investing in our short-form video content, creator-led content, native content ecosystem to address exactly that point. We think that's the path toward enriching the user experience and building connections to shopping experiences over time that will drive frequency of use, more people to the platform, and over time, a connection to shopping and commercial activity that will differentiate the platform, both with respect to users and advertisers. That's the overall longer-term answer.
We're also focused on making the user experience more rewarding this year by leveraging the data we have, increasing personalization, improving our recommendation engine, so continuing a lot of the things that we've talked about over the last couple of years to further build out a really rewarding user experience. I think that will drive more people to the platform for more things in their life, more session frequency, and ultimately more conversions and economic activity. I don't know if it came through clearly before, but in terms of stability, we're looking at a couple of things. One is last quarter, we talked a lot about the pandemic impact. We had the benefit of the pandemic from an engagement standpoint. When folks locked down, user behavior shifted to more at-home use cases versus out-of-home use cases.
Because of our strength in use cases associated with at-home activities, we benefited. That reversed last year in the spring when out-of-home use cases became more prevalent and we saw the unwinding of some of those engagement gains and user growth. We from Q3 to Q4 did see a large impact globally and in the U.S. from the search algorithm changes from Google. Sequential growth, the bulk of that decline, Q3 to Q4, was not pandemic-related. It was more related to search algorithm changes that drove less search-related traffic to Pinterest. If you stripped out the impact of that, we were actually up in terms of direct mobile app users globally in the high single digits year-over-year. Internationally, we were up 11%. In the U.S., we were down around 6%.
Much more resilient engagement with respect to the users who are the deepest, most dedicated, resilient users who drive the bulk of our impressions, time spent, and revenue. I don't know if that's helpful. Ben, I don't know if you wanna, you know, pile on with respect to the investments we're making in product.
Yeah, Pat, I think you did a great job giving an overview. You know, Mark, the only thing I would add is, you know, we've talked about kind of three different kind of investments that we're making, investment in creators, an investment in shopping, so when people see things, they can buy them, and then, of course, investment in our core personalization and discovery experiences.
If you take a step back as a user, like, our aspiration is to build one coherent experience where all three of those things play an important role. Today, you know, there are places to connect with your friends, there are places to be entertained, but our vision is to build kind of an inspiration to realization platform where you visit, you connect with creators that are aligned with your interests, we understand your taste, and we recommend individual products, and then you can eventually buy those things directly. That end-to-end experience is something that doesn't exist online. These three investments will play out over time. I would say the creators is the earliest. Most of those features just launched in October, but it adds an important new element. This year, we'll continue to improve our shopping experiences.
We'll expand our test of native checkout. We'll build more dedicated and personalized services on top of a shopping API. Then we're always investing into that core personalization relevance, and that's really been buoyed by advances in machine learning, and computer vision, which are core competencies for the company. Pinterest is really charting a different course. You know, I know in these calls, everything gets reduced down into time spent and ads, and those are, of course, fundamental things that we look at all the time. But we're really focused on owning this inspiration to realization space in the market. We think that's very differentiated from social networks and from pure entertainment platforms. The three investments that Todd mentioned on creators, shopping, and personalization are all driving towards that common vision.
Thank you, Ben. Thank you, Todd.
Our next question comes from Brian Nowak of Morgan Stanley. Brian, please go ahead.
Sure. Thanks for taking my question. Let me ask one about the investment areas on the advertising or the monetization side. I mean, I know you typically have a pretty robust pipeline of different types of innovation that you're focused on to deliver more return for your advertisers. As you look into 2022, what are the products or areas, Ben, where maybe you're most excited to really invest in and roll out that you think can really move the revenue for you and also really deliver more return for your advertisers throughout 2022?
Sure, Brian. I'll talk about four kind of themes that our advertising and shopping teams keep in mind, and then I'll go into them in a little bit more detail. The first one we talked about before, but it's automation. We're gonna continue our automation journey, especially automating ad campaign management. The second is gonna be relevance and optimization. Third, which Todd touched on, was international expansion, and then finally shopping. I'll just, like, walk through them individually, and I think together they'll give you some more color on the journey that we're on. Look, just starting with automation, we still believe that we have a lot of runway as we automate ad campaign management.
I mean, our goal has always been that an advertiser should be able to show up with their budget, their goals, and their content, and Pinterest should take care of the rest, and we're still pretty far away from doing that. In the past, you heard us talking about bidding automation, but this year our investments are really directly linked to providing more value to mid-size and small advertisers that are a natural fit for Pinterest. That should result in increasing the efficiency of our ads marketplace, and delivering greater value. You know, second is relevance. You know, this is sort of this thing that never stops, but we really believe we have room to improve our relevance engines, which should further improve the efficiency of our ads.
Again, underlying that is leveraging our Taste Graph and leveraging machine learning, so when people see ads, they feel just like content. Third, we talked a little bit about international advertisers. I thought Todd did a great job of covering that, you know, we're expanding to new markets, and I'm really excited that the team that we built there and the playbook that we developed over the last few years. We're kind of learning with each subsequent market how to get on our feet a little bit quicker. Finally, when we look across all of our surfaces, we know that the shopping surface in particular, the surface with the highest commercial intent, still has huge headroom for monetization.
You know, we're investing in building that great consumer experience first, but we see year-over-year increases in the number of people doing product searches, amount of time that they're spending on shopping surfaces, and we're also simplifying our shopping ad formats, so brands can just more easily promote their products. There's a lot there. You know, we'll be experimenting with Idea Pins monetization. We expect that to lag. We're gonna wait for that creator economy to sort of get up to speed, but we think there are some pretty significant drivers of future revenue growth that we're still in the early innings of pursuing.
Great. Thanks, Ben.
Our next question comes from Rich Greenfield of LightShed Partners. Rich, the line is yours.
Hi. Thanks for taking the question. You know, like, last year there was obviously a lot of speculation surrounding Salesforce acquiring you or looking to acquire. I guess the question is, you know, especially when you sort of highlight, Ben, the challenges of platform changes and how tweaks, you know, I guess you looking at what happened with iOS 14, 15 and Meta, looking at sort of the way Google can change their algorithm. I guess it all just sort of begs the question is, size and scale look increasingly important in the broader media tech ecosystem, and I guess, you know, even commerce ecosystem I would say. How do you think about sort of where Pinterest fits in? Are you open to consolidation?
Like, how do you think about sort of where ultimately you need to be to accomplish what you want?
Sure, Rich. Well, I think, you know, there are two parts to the answer. You know, first, like, as CEO and fiduciary, I'm always keeping an open mind. But I really do believe that we have a pretty unique place in the market. I touched on it before, but, you know, I can go into a little bit more detail. You know, first, you know, there's a huge audience that's coming to Pinterest for something that's fundamentally different than when they come to other platforms. They're not coming to connect with friends
They're actually coming to envision their future and to plan for it. Increasingly, we're getting better and better at helping them do that planning, by connecting with the people that can share the knowledge and the inspiration to advance that, and then eventually connecting to the retailers and to the individual products they need. I really think that, you know, planning your future, that's a fundamental human need that's not going away, and we're laser-focused on targeting that need above all the other ones. You know, the second thing I'd say is that, you know, Pinterest sits at this pretty interesting intersection of a few trends that are really secular growth trends in the industry. You know, commerce is one of those.
We have a lot of people coming with specific intent to do something, but they may not have settled on the specific product they're looking for. I think that space of shopping, not just buying, but actually shopping, discovering what you're looking for, finding something that aligns with your tastes, that's still quite open. Finally, you know, we're investing in the creator ecosystem and online video, and I truly believe that video and mobile video is still in its infancy as an industry. I believe that we're gonna see verticalization happen over time, and we're well-positioned to pioneer new media formats to be both inspiration, but also allow creators to facilitate action in providing different revenue models for them and being, you know, a real source of economic growth for that new creator business.
Just to be clear.
That's kind of what we've laid out over the last few years. Yeah?
Just to be clear, when I think Todd made a comment about the potential risk to growth on sort of engagement, tied to competition, I mean, are we speaking specifically about TikTok, or is there something else beyond something like TikTok that you're looking at competitively that could have impact in the future?
Sure, Rich. I mean, look, we take all competition seriously. I would argue that competition for kind of user attention and time right now is probably the most competitive industry in the world. Of course, TikTok, we think about. We think about Meta, we think about Google, but we also really try to focus on what we can offer that's differentiated, and that was the spirit of the last answer. I hope that's helpful.
Got it. Yeah. Thank you.
Our next question comes from Doug Anmuth of J.P. Morgan. Doug, please go ahead.
Great. To both of you, thanks for taking our question. To the first one, do you have any views to share on why Google algorithm changes are impacting you guys more recently and how to think about direct traffic mix, this year and then going forward? Secondly, could you give us some update on where you are with the native checkout and the timing for that moving beyond just the test phase?
Yeah, I think, a couple questions in there. One was around direct traffic and search-driven traffic, and then the other was on native checkout. On the second, we just started piloting and testing native checkout, and we look forward to continuing to scale and broaden those efforts over the course of the year, so it's still pretty early days. On the direct traffic mix, I tried to lay out a couple ways I've been thinking about it. One was the bridge on sequential and year-over-year trends with respect to MAUs, and I wanted to give you a little bit more color on that direct usage, mobile app usage, to give some color on the difference between search-driven traffic and search-driven MAUs versus those that are direct for the reason that you described. The truth is that Google makes algorithm changes regularly.
We did see another one in November that had a material impact, which is why we're calling it out. It's not the first time it's happened, and we are working on how to best factor that into our product mix and respond to it. The long-term answer is to have a robust native content ecosystem, which we're building, and I think that'll be the long-term answer on engagement.
Got it. Thank you.
Thanks.
Our next question comes from Colin Sebastian from Baird . Colin, please go ahead.
All right. Thanks, guys. Good afternoon, two for me as well. I guess, first off, I wanted to follow up on some of the disparity in performance between the mobile app and desktop. I know a lot of the work you've done on personalization and native content, for example, might be more concentrated in the app. If that's true, is the app, you know, usage and engagement level or trend, is that a better gauge for what overall the platform might look like down the road, in terms of engagement? And then secondly, I know you added a Chief Content Officer from YouTube. I think Malik's experience was with a lot of premium content and native content creation.
I'm wondering if YouTube's strategy in those areas serves as somewhat of a template for what you hope to achieve with respect to video brought onto the platform. Thank you.
Colin, why don't I start with the question on the search-driven traffic, and then I'll let Ben talk about the team, and leadership piece. We've talked, you know, when we were marketing the company on the roadshow, we talked about a lot of our user growth being different on Pinterest versus social media. It's not a viral product where if you join, you immediately invite seven of your friends. It's much more linear in terms of growth, and it's driven largely by word of mouth. Search-driven traffic is kind of a way of getting word of mouth, and it's automated. You're looking for a new idea, you have content that's recommended to you, and you discover Pinterest. It's an important top-of-funnel growth driver, and it's also an important revisitation driver.
For those reasons, we think it's an important part of our engagement because it's a source of revisitation and therefore reducing churn. Ultimately, our MAUs are a byproduct of that, and it introduces people to Pinterest potentially for the first time to solve new problems in their life. I wanted to give the color on the mobile app usage because that is where people spend the bulk of their time, impressions, and revenue opportunity, but the two are very important when considered together. That's why we've broken it up the way we did.
Yeah, Colin, and you know, as you pointed out, you know, we welcomed Malik from YouTube as our first Chief Content Officer. It kind of reflects the role and the importance of content on the platform going forward. Look, I would say that there are a few things. You know, one is, as a company, you know, we have a lot to learn about audience development, and we're really impressed with kind of Malik's analytical problem-solving as well as his experience in both kind of premium and user-generated content. You know, the other thing that I was really interested in is that, you know, Pinterest really wants to be a place where the content that we serve to folks is nourishing, is positive, and is inspirational.
I think over the last few years, a lot of our users have appreciated that while many services online kind of have quite a bit of polarization or toxicity or sometimes content that they don't feel like is enriching, Pinterest has tried to have a little bit of a tighter focus on something that's positive and inspiring, and that's because that's core to our mission, right? If you're thinking about being inspired for your life, it's important that you're in an environment where the content is positive overall. Looking at some of his experience working with more positive content ecosystems, whether it's like YouTube Kids or on the premium side, I thought brought some really important insight.
You know, I'd also share that, you know, we're building a whole team, and so, you know, there's always a lot of attention on leaders. But, you know, I'm excited about the team's ability to move fast and innovate, and really chart its own path because I think that all of these content platforms, while in their initial days they may look similar, they're gonna end up looking different and verticalizing. We're gonna need to really follow kind of the Pinterest users, and develop a content offering that really works towards our mission, of inspiring them in their day-to-day life.
Great. Thank you.
Our next question comes from Lloyd Walmsley of UBS. Lloyd, please go ahead.
Hi. Yeah, this is Akash Agarwal on for Lloyd. Two questions, if I may. The first is, can you talk about trends in higher frequency metrics like weekly active users or maybe overall time spent? Are you seeing this outperform relative to MAU? The second question would just be, you mentioned how some of the newer formats are driving increases in frequency. What are you seeing with respect to shopping in particular? Are you seeing, you know, consumers who leverage the shopping functionality actually come back with greater frequency? Or is it more, you know, story pins, Idea Pins, and videos? Yeah. Thank you.
I can start. Thanks for the questions. On the additional metrics that you were asking about weekly active users, time spent, et cetera, we do disclose a ratio in our public filings on an annual basis around weekly active users as a percentage of monthly active users, and that's been pretty stable over the last few years. That's the answer on one. With respect to shopping, you know, we are seeing a much better user experience enabled by a lot of the investments we've been making over the last few years, dedicated shopping surfaces that allow users to go from idea to purchase in a much more natural kind of shopping in a much more natural shopping journey.
At the same time, we've dramatically improved the amount of inventory we can serve with our catalog ingestion work and the APIs that we've developed. As a result of that, we've seen a number of users who are engaging in shopping surfaces grow pretty meaningfully. We're up 20% sequentially from Q3 to Q4 and 20% year-over-year. Really encouraging, and I think there are a lot of connections that we can build over the next few years across this native video ecosystem, our creator-led content ecosystem, coupled with a lot of the shopping investments we're making should make a really differentiated experience on Pinterest.
You may have also noted that we got some press a couple of days ago on the AR, some of the AR products we've been shipping that have really improved from a technology perspective, our ability to deliver pretty interesting shopping experiences. Really excited about some of the innovation that our teams have built.
Thank you.
Your next question comes from Justin Post of Bank of America. Justin, please go ahead.
Great. I'll ask just one. You know, revenue's really accelerated during the pandemic and you're able to reach 32% margins for EBITDA last year. Just looks like you're gonna be doing some more investing next year. What have you learned about the margin potential of the business and any update on how you're thinking about long-term margins? Thank you.
Thanks, Justin. While we did have a, you know, a kind of a banner year with respect to performance, gross margins were at incredibly high levels by the end of the year. Our spend profile, you know, we continue to invest aggressively. Our headcount growth, I think a year ago, was like 15% in the fourth quarter. That ticked up a few points every quarter until we got to 27% in the fourth quarter of this year. We're investing a lot further, you know, more headcount growth going into next year. I think what we've proven is that we have a great business model and that the business is working.
I think we've also internally come to the view that the long-term potential of the company needs to be enabled by further investments over the course of this year, which is how we landed at the guidance that we suggested, which is a lot of confidence that when we make investments with the right plan. We know what we're looking at to gauge success, and we hold ourselves to that from an execution standpoint. We have a pattern of delivering great results. That started a few years ago when we were rebuilding our international audience. Our growth rate in international users had been ticking down, and with concerted effort, the right investment plan and great execution, we turned that around and re-accelerated our user growth outside of the U.S. That was fantastic.
We built a monetization plan in the U.S. that was forward investing in building a business, and that worked well. We did the same thing for international monetization, and again, we've talked about this in the past, put a lot of investment in creating a compelling shopping experience from a user perspective and are now building a business around that. I'm confident that like all of those other projects, our long-term focus, the strategic, outcomes that we're looking for are the right answer for this business over the next few years, and accelerating our investments again next year will help us deliver against that. Is that helpful?
Yeah. Great. Thank you.
Okay.
Operator, we'll take our last question.
Our final question will come from Rohit Kulkarni of MKM Partners. Rohit, please go ahead.
Hey, thank you. Two, if I could. One is just in the past, you've commented on in-home versus out-of-home use cases and kinda underlying engagement trending one way or the other. Yeah, I just find it curious that the only creator that showcased in the letter is a travel blogger. So if you could just comment on, like, how is the engagement for, say, out-of-home, say, travel, beauty trending versus in-home use cases? And another question is on managed versus full kinda automated advertising campaigns. If you could just call out what type of advertisers are choosing one versus the other.
Is there a pathway that you think that an advertiser goes from a managed full funnel ad campaign to a completely automated ad campaign? So those are the questions. Thanks.
I'll start with the second question. I think, we've seen a lot of success in our managed advertising community, those that we cover both with respect to field sellers all the way through our kind of mid-market coverage team. We've been making a lot of investments in automating our ad stack to make it easier for those advertisers to onboard, scale their spend, and increasingly see the results of that spend. We're not at the point yet today where that experience is as fully instrumented as we would like it to be to have an unmanaged long-tail advertiser base on the platform. We've been focusing on the managed go-to-market model until we get that up and running. We've been making all the right investments, seeing all the right returns with respect to building that ad stack.
It'll just take some time before we get there. That's one. I don't know, Ben, if you wanted to talk about use cases.
Yeah. Rohit, you know, I mean, Pinterest's use cases have often reflected what's going on in broader society. So, you know, as Todd mentioned, we saw a big change with the outbreak of the pandemic, and hopefully we're seeing a little bit more of a return to normalcy. I think we're all hoping for that. I'll also say, you know, on Pinterest itself, we've always had historical strength in some core lifestyle verticals. One of our hopes is that as we scale the creator ecosystem and give creators the ability to directly build their own communities on Pinterest, we'll start to see some expansion and see different types of use cases emerge. Still early days, but again, it's kind of one of the benefits if we can build that ecosystem.
We're excited to continue investing in that, because we think it'll advance our mission of inspiring people and helping them create a life they love.
Great. Thank you for joining our call, everyone, and we'll see you next quarter.
This concludes today's call. Thank you for joining. You may now disconnect your lines.