Good day. Welcome to the Youdao 2021 first quarter earnings conference call. Today's conference is being recorded. At this time, I would like to turn the conference over to Mr. Jeffrey Wang, investor relations director of Youdao. Please go ahead.
Thank you, operator. Please note the discussion today will contain forward-looking statements relating to future performance of the company, which are intended to qualify for the safe harbor from liability, as established by the U.S. Private Securities Litigation Reform Act. Such statements are not guarantees of the future performance and are subject to certain risks and uncertainties, assumptions and other factors. Some of these risks are beyond the company's control and could cause actual results to differ materially from those mentioned in today's press release and this discussion. A general discussion of the risk factors that could affect Youdao's business and financial results is included in certain filings of the company with the Securities and Exchange Commission. The company does not undertake any obligation to update this forward-looking information, except as required by law. During today's call, management will also discuss certain non-GAAP financial measures for comparison purpose only.
For the definitions of these non-GAAP financial measures and reconciliations of GAAP to non-GAAP financial results, please see the 2021 first quarter financial results news release issued earlier today. As a reminder, the conference is being recorded. Besides, a webcast replay of this conference call will be available on Youdao's corporate website at ir.youdao.com. Joining us today on the call from Youdao senior management is Dr. Feng Zhou, our Chief Executive Officer, Mr. Lei Jin, VP of Operations, Mr. Peng Su, our VP of Strategy and Capital Markets, and Mr. Wayne Li, our VP of Finance. I will now turn the call over to Dr. Zhou to review some of our recent highlights and strategic direction.
Thank you, Jeffrey, and thank you all for participating in today's call. Before we begin, I would like to remind everyone that all numbers are based on CNY. We achieved strong and sustainable growth across our businesses in the first quarter of this year. Total revenue in Q1 was CNY 1.3 billion. Net revenue from K-12 is CNY 639 million, up 217% year-over-year. Meanwhile, gross billings from K-12 reached CNY 442 million in this quarter, up 130% year-over-year. Paid student enrollments from K-12 climbed to 306,000, up 100% year-over-year. With larger scale, we have also achieved higher operating efficiency. Gross billings from K-12 and adult segments reached approximately CNY 742 million. Brand and performance advertisement spending on courses amounted to approximately CNY 556 million.
Compared with Q3 2020, the last quarter with mostly new student acquisitions and almost no renewals, our return on investment, or ROI, improved by more than 30%. Gross billings from the adult segment reached CNY 299 million in the first quarter of this year, up 17% year-over-year. Remember that the outbreak of COVID-19 in Q1 2020 led to a higher base and thus more moderate year-over-year growth of the adult segment. Margins were also improving. Gross profit margins from learning services reached 65% in the first quarter of this year, up from 51% in Q1 2020. It is the best level since we became public. Operating loss margin narrowed down to 23.9% in the first quarter of this year compared with 32% in Q1 2020. With that financial overview, I'd like to review some student highlights.
Looking at our K-12 segment, we launched the industry's first localized version of junior high school Chinese with two instructors during the spring semester in Q1. One instructor covers nationwide content and the other covers localized content. More than 50% of our junior high school Chinese course students opted for this localized version of junior high school Chinese, reflecting high interest in this course format. Course participation and satisfaction data were also promising. As for high school and primary school students, we continue to polish courses and offered more tailor-made math content to students of different learning levels. Gross billings of high school math increased by over 210% year-over-year in Q1 2021. We had 197 instructors and 4,093 students at the end of Q1 2021.
For our extracurricular segment, Youdao Weiqi or Youdao Zongheng in Chinese, we maintained a strong momentum from last quarter and achieved more than 100% quarter-over-quarter growth in gross billings. In the meantime, Youdao Zongheng sponsored the Jiangsu Weiqi Youth Team. We signed Ke Jie, eight-time Weiqi world champion, as our brand spokesperson. As for our adult segment, in March 2021, we established adult education business units. This puts several teams under the same umbrella, including the adult-oriented courses in Youdao Premium Courses, NetEase Cloud Classroom, and China University MOOC. New courses will be released under the NetEase Cloud Classroom brand, concentrating our investments in a single brand. According to our data, the extraordinary memory course has become the number one memory-oriented course in the industry only three quarters into its operation. Our intelligent learning devices also grow at an accelerated clip in Q1.
I'd like to highlight that gross profit margin hit 44% in the first quarter, a record high for our devices, compared with 25.6% in Q1 2020. In March, we introduced Youdao Dictionary Pen 3 Pro, further supporting bilingual translation of Japanese and Korean to meet the demand of more language learners. We shipped over 297,000 units of our Dictionary Pen series in Q1, up 198% year-over-year. We are only getting started. We have more device products in the pipeline for 2021, and our teams are very excited about them. As for our mobile learning apps, we launched a short video feature called WOW Community, WOW Quan, in Youdao Dictionary. Users and content creators could finally share short videos about learning and fun things in their life in Youdao Dictionary.
This led to users staying much longer on Youdao Dictionary. That is more ways for us to engage with our users down the road. This, along with other improvements of our apps, facilitated organic traffic growth. In the first quarter of this year, 26% of all newly enrolled students' gross billings came from organic traffic. Gross billings from the K-12 segment generated by organic traffic increased by 129% year-over-year. Let us quickly discuss the potential additional regulations on the AST market. The new regulation is not out yet. Obviously, we will not know the details until it is out. With that said, we continue to hold a cautiously optimistic attitude towards business operations under the new regulatory environment. We believe the purpose here is to curb unorderly competition and promote healthy development of the industry.
This will ultimately benefit highly compliant players of scale in the mid to long term. We believe our product and strategy are very competitive with our high-quality content and recently advanced application of AI technology. Our diversified business lines, including learning devices and adult courses, could help us better navigate the evolving online education industry. Now let us turn our attention to other aspects of the company. We pay attention to fulfilling social responsibilities while we operate our business. In Q1, we made several donations, including to Leibo Middle School in Liangshan, Sichuan province. NetEase donated CNY 66 million to the Yau Shing-Tung Science Foundation to support its math research. We are looking forward to further cooperation with Mr. Yao's team in AI and basic education areas. As we are still working towards profitability, in Q1, we secured additional funding to support our long-term plans.
We raised approximately $232 million through a follow-on offering in February. NetEase recently offered us a $300 million loan facility agreement. In addition, a bank group provided a commitment letter in April with a three-year $150 million revolving loan facility under the guarantee of NetEase. In total, that is over $680 million of additional funding. Looking ahead, we are confident we can build on our position as a top-quality course provider and producer of industry-leading intelligent learning devices, services, and products to meet our customers' needs. Our diversified business model, along with products and technology that truly improve learning efficiencies, will help us navigate the evolving AST and EdTech markets. With that overview, I will now turn the call over to Peng Su to review our financial results. We will then open to questions. Peng Su?
Thank you, Dr. Zhou, and hello, everyone. Today, I will be presenting some financial highlights from our 2021 first quarter. We encourage you to read through our press release issued earlier today for further details. We started the year with a robust first quarter, with multiple operational and financial achievements. Total gross billing from our online courses reached CNY 808.7 million for the first quarter, up 55.9% from Q1 2020. Of course, billing from our Premium Courses rose to CNY 741.5 million, up 66.2% year-over-year. Our K-12 segments continue to lead our growth, reaching CNY 442.2 million in gross billing in the first quarter, up 130.2% year-over-year. Paid student enrollments from our K-12 group reached 306,000 in Q1, up 100.3% year-over-year. Paid student enrollments for Premium Courses were up by 75.6% year-over-year.
29% of our K-12 new enrolled students gross billing came from organic traffic for Q1, which grew 129% year-over-year. This growth shows not only our determination, but our ability to quickly expand our business and that our model is working. For the first quarter, total net revenue reached a record CNY 1.3 billion, or $204.5 million. This represent an increase of 147.5% from the first quarter of 2020. Looking at this growth by segment, net revenue from our learning services were CNY 998.9 million, or $152.5 million, up 156.8% from the same period in 2020. We attribute this growth to the increased revenue generated from our online courses, which were further driven by a substantial increase in paid student enrollments for the K-12 courses of the Youdao Premium Courses.
Net revenue from our learning products were CNY 201.9 million, or $30.8 million, up 279.8% from the same period in 2020, driven by increased sales of our Youdao Dictionary Pen of over 297,000 units in the first quarter. Net revenue from our online marketing services were CNY 139.1 million, or $21.2 million, representing a 40.1% increase from the same period in 2020. For the first quarter of 2021, our total gross profit greatly improved, reaching CNY 767.5 million, or $117.1 million, up 225.6% compared with the first quarter of 2020. Gross margin for learning services increased to the 65.6% for the first quarter of 2021, up from the 51.9% for the first quarter of 2020. The growth was primarily attributable to better economic scale and the further optimization of our faculty compensation structure.
Gross margin for learning products increased to 44.1% for the first quarter from 25.6% for the same period in 2020. The growth was driven by tremendous growth in sales of our Youdao Dictionary Pens version 3, which carry a higher gross margin profile than other learning products. Gross margin for online marketing services was 16.4% for the first quarter of 2021, compared with 20.5% for the same period in 2020. The decrease was mainly due to the increase in performance-based advertisement through the third-party internet property, which carried lower margins. For the first quarter, total operating expense were CNY 1.1 billion, or $166.1 million, compared with CNY 411.7 million for the same period last year. We continue to invest in our future and the top-line expansion, specifically technology, acquiring talented teachers, and the sales and marketing efforts focused on student acquisition and expanding our branding awareness.
In Q1, brand and performance advertisements spending on courses amounted to approximately CNY 555.9 million. For the first quarter, our sales and marketing expense were CNY 883.9 million, compared with CNY 299.2 million in the first quarter of 2020. Research and development expense were CNY 555.1 million, compared with CNY 84.1 million in the first quarter of 2020. Our operating loss margin was 23.9% in the first quarter of 2021, compared with 32.5% for the same period of last year.
For the first quarter of 2021, our net loss attributable to ordinary shareholder was CNY 325.8 million, or $49.7 million, compared with the CNY 169.4 million for the same period last year. Non-GAAP net loss attributable to ordinary shareholders for the first quarter was CNY 307.8 million, or $47 million, compared with CNY 161.9 million for the comparable period last year. Basic and diluted net loss per ADS for the first quarter was CNY 2.75, or $0.42.
Non-GAAP basic and diluted net loss per ADS for the first quarter was CNY 2.6, or $0.4. Our net cash used in operating activity for the first quarter was CNY 517.8 million, or $79 million. Looking at our balance sheet as of the March 31st, 2021, our contract liability, which mainly consists of deferred revenue for our online courses, were CNY 1.2 billion, or $186.5 million.
Compared with the CNY 1.4 billion as of December 31st, 2020. At the end of the period, our cash equivalent, time deposit, and the short-term investment, total CNY 2.2 billion, or $333.7 million. This concludes our prepared remarks. Thank you for your attention. We would now like to open the call to your questions. Operator, please go ahead.
The first question comes from Sheng Zhong with Morgan Stanley. Please go ahead.
Hi, good evening, management. Thank you for taking my question. I have two questions. The first one is, can you share more color about the current promotion and advertisement status on the market, what's your promotion plan for the summer holiday? Do you have any budget to share with us? Marketing budgets. Secondly is, we know there were a lot of uncertainties about the regulation. Can you please share some more about your operation, like the retention rate after your localized content, also what's your current growth target for K-12 as a switch between business? At the same time, we see with the regulation tightening or uncertainty and a lot of competition increase in the non-K-12 segment, including the hardware learning devices and also adult education.
What's your view about these sectors, the growth, and whether you will also invest more in this non-K-12 business? Thank you.
Thanks, Sheng. Regarding the current promotional activities on the market. The first is that currently we are running advertisements on non-mainstream media only. Recent changes doesn't allow AST business to run ads on the mainstream media anymore right now. We're running ads on the non-mainstream media and also the scrutiny for the ad materials become stricter. From our side, we have always been fully compliant with the regulations. We think it's a smooth process one. We do need some changes, but the changes are not much. That's the current update on the ads. As you probably know, we have suspended advance enrollments and fee collection for the fall semester as required by the authority. These courses will be sold at a later time. Right now, only spring and summer semester courses are being sold.
Overall, we have already been frequent compliant with the current regulation. Regarding the new regulation, it's not out yet, so we don't know the details. As I said in the remarks, we are cautiously optimistic about the coming future operation, in particular, the summer operation. Obviously, there's a cost to being compliant under stricter regulation. We will understand that when it's out. However, we have a couple of reasons that we think we can be cautiously optimistic about. First is the leading companies used to be more happy, more compliant, and compared with the smaller ones. Relatively speaking, the leading companies could be at an advantage here when the new regulation is out. Also, as we talked about, Youdao has a diversified business line.
This is basically a choice we made a couple of years back, not for regulation per se, not for being compliant per se, but more for broadening our potential for innovation. Surely it benefited us. However, diversification obviously has its benefits when there is more regulation. Our learning devices and adult education business will probably not be impacted by this round of regulation as far as we know. For the summer, basically, the current actions the teams have taken is that we get several plans ready for the summer. The structure of the courses will be a little bit different. As far as we know, we think we will have solid plans to execute when the regulation comes out. Again, we remain cautiously optimistic. Lastly, I want to mention that the industry has sort of a theater effect. It's not a good thing.
Everybody goes forward. For example, institutions compete to set their enrollment dates earlier and earlier every year. Yeah. Now the enrollment dates are pushed back kind of together. In our experience, we think this leads to more orderly business. Actually, the date when it gets closer to when the course starts, actually conversion rates get better. That's our view on the regulation and the summer plan. We have a couple of plans ready. We will know which plans execute when the regulation actually comes out. I think you also asked about more competition on the non K-12 front, hardware adults. Obviously this overall kind of new direction plays in our favor, I think. We have been working on the hardware business for three, four years now. Almost four years. We all know that it's really hard to make devices.
A lot of challenges. How do you manage inventory? How do you manage your supply chain? What if the products are faulty, quality issues? A lot of that. We have gone through all that. We think it is a good thing, actually. More and more people pay attention to learning devices. Other people, when they go through advertisements, it also helps people pay more attention to the whole segment. We think it's a way to build the segment as industry. We think we're not worried about more competition and obviously we will treat every competitor very seriously. Pay a lot of attention. We think it's a good thing that people are paying more and more attention to these segments, and it's a testament to the strategy that we set some time ago.
Yeah. Thanks.
Yeah, just one more point with the doctor's comments. Yes, the first is about definitely Youdao right now is strictly in compliance with all existing regulation as well as definitely we are fully confident about to be compliant with all the upcoming regulations along in the future. Just like doctor mentioned, although there are some effects on the mainstream medias for the advertisement. Right now for the new media platform, as well as some Internet and as well as the mobile net, maybe the social network right now it didn't change by now, we can just do execute our plan for the advertisement for the customer acquisition by now. Let's go back to the regulation questions. Definitely we will keep our eye open to watch closely about regulation movement, and definitely we will put ourself into the compliance with the upcoming regulation.
Thank you.
Thank you very much.
The next question comes from Brian Gong with Citigroup. Please go ahead.
Yeah, thanks management for taking my question. My question is still regarding the regulation. Given the current regulatory environment, so can management share our growth strategies going forward for the whole company? Do we figure out any new ways to gain students? Yeah. Another quick question is about our GP margin of learning services, which jumped a lot in the fourth quarter, and may we know the reason behind this? Also, how should we look at the trend ahead? Thank you.
I'll take the first question. Regarding new ways to acquire customers. We are obviously, as we talked about in meetings before, so we are looking at many different fronts, including customer referrals and expanding of the existing customers. These actually have recently picked up really well. Also, another area we are putting a lot of efforts into is conversion of our organic users. As we just talked about, 36% of K-12 both billing actually come from our organic traffic. In Q1, the WOW Community, the short video community on the Youdao Dictionary, actually is a good example of that effort. Because short video becomes really popular given that the cost of the bandwidth has really come down to near zero. Also, the young generation really loves to watch videos on their cell phones.
We have been working on that for some time, and really Q1 is the quarter where we released it and actually really already get very good results. As we said, the average time a user spends on the dictionary actually doubled because of this feature. Yeah. It's a very good feature. Because these short videos, we can show a lot of contents with this media. One of the key types of content is actually conversion to our courses. Yeah. We also have some progress on the offline channels. There are many different ways to do offline conversion. We have some that has already yielded good results and on the other hand, some we are still working on them. Overall, put together, the teams are confident that they can do a good job.
Even if we do get some loss from the regulatory front, the other channels can make up most, if not all of the losses. We think we are cautiously optimistic about it. Yeah. I don't know, Su Peng, if you have anything to add.
I guess one more point to add, and it's just as you asked, Brian, and you asked about how we grow our business, and besides what doctor mentioned regarding how we handle about the impact on our business for the K-12 potentially by the potentially possible upcoming regulations. Also besides the K-12 business, we also operate several multiple business under Youdao, like the adult education business as well as the hardware business. We don't think we have any impact on the upcoming, potentially or possible upcoming regulations. For those two business, we operate over several years, and we have already had some more experience and some insight about how to operate that kind of business, whether for the adult education or the hardware business. We think about we build some of the barrier in these sectors.
We also can just grow our total business. We are driven by the K-12, as well as the adult and the hardware business. In the long run, that's our expectation of our business futures. Besides all the K-12. Go back to the K-12, whatever we think fundamental thing for the K-12 business is about the content of product, because all the parents really care about the quality of the courses we offer to their kids and students. Just like doctor mentioned in the call, and we are the first one to offer the localization content for the junior high school Chinese for the online big class new business model, and we even increase one instructor as a localization content instructor into that model. We receive very positive feedback from parents and students.
We think about we will create more innovative way to deliver our content and deliver our products and deliver the message to our student and users to try to leverage more beneficial for our product and content upgrade. Thank you, Brian.
For the second question, the gross margin of our learning services. We got good performance at the gross margin improvement during this quarter. It is the first quarter to achieve over 50% of GP margin on learning services segment. We believe the most key point is our capability to offer a good quality service or product with good price, which is further driven by our good instructors and technology, and the synergy of the product and our other businesses. We will insist on the strategy and invest more on it. In detail, the continuous economic scale on revenue and the competition structure improvements, as we mentioned before, mostly contributes the improvement in GP margin. As for the competition structure stability of cultivating young instructors is the key to make us maintain good stability to improve our cost structure.
This quarter's high GP margin mainly contributes from our high revenue base of our online courses, because more courses are delivered in Q1. We believe maybe there's some seasonal effects in our learning service GP margin. In the long run, we reasonably believe the annual growth margin on our learning services will be back to around 6% in this year. I think maybe it's helpful for your question. That's all.
Thank you. That's very helpful.
Once again, if you have a question, please press star then one on a touch-tone phone. The next question comes from Hongyi Zhao with CICC. Please go ahead.
Hi. This is Hongyi from CICC. Congratulations for the great performance this quarter. I have two questions. Since you have introduced many business strategy for the non-K-12 business, does this mean based on the policy uncertainty for the K-12 business, are we going to switch our attention or put more investment to the adult business and learning projects in the future? What's the strategy for the long term? The second question is, are we going to develop more offline development strategy, such as, opening some experience stores as one of the traffic acquisition strategy? Thanks.
Yeah, I will take the first one. Regarding investments in the non-K-12 segments. I would say that when we did our planning for 2021, we've already taken into account the growth needs of the hardware and also of the adult section for us. Currently, we will keep on executing that plan. We don't actually foresee significantly different plan to invest in other segments than K-12. We think both hardware and adult are very interesting and very promising. I would use this opportunity to maybe talk a little bit about our thinking behind the adult education segment. The main point is that we believe on the long-term potential, and we have leading assets and experience. We think this is a good fit for us. Lifelong learning in China, we think it's really going to take off.
It's a very clear trend because the economy continues to grow, and more and more people will realize that they have to, they need to, and they will like to be a lifelong learner. That's where our adult education products are really positioned at. If you look at the sector's history, the Chinese adult education industry, really a sector, has a long history. We see that there are a couple of verticals that really stand out. The first one is ESL, English as a second language. The second one is civil servants exam test prep. Yeah. These two verticals are really good examples of successful business. They have reached the billion-dollar annual run rate business level. I think what's going to happen in the future is, first there will be new verticals. These two will not be the only verticals that become large business.
There will be new verticals, then there will be new models for existing verticals. That's basically the approach our teams think about it. When we look at some vertical, we think whether we have some way to reimagine it or do we see some new vertical that really has the potential to be as large as civil service test prep or English as a second language. For example, our ESL course, including really popular Yang Liang's English course, it's already quite popular. Yeah, these are basically reimagining of the existing verticals, English learning. Yeah, I don't have time to talk about details, but for anyone who's tried those courses, they will see that it's really innovative. Yeah, for new verticals, we are already seeing potential ones. For example, our extraordinary memory mini-course is really picking up.
What others are doing, like personal finance skill courses, [Non-English content]. Yeah, these are all also quite popular and promising. This is our thinking behind the adult education sector. We think it's really promising, and we will take the long view, and we will focus on that.
Thank you.
For the second question, about our offline stores strategies and how we develop our ground-level customer acquisition strategies. The follow-up point is we actually have disclosed in the last several quarters in our earnings, we mentioned about we have set up some offline education stores. This is not a learning center, because we didn't give any services in that store. In the different provinces, we test about how can we look for the best strategy or the best solution for the offline or the ground-level customer acquisitions for online education business operators.
We think we are still on the way because we just started a couple of months ago, and we see the very promising feedback from the data. Right now, it's still in a very small scale, so we didn't expand the scale too much in the last couple of months. We think about it, probably we can share more information regarding these issues if we achieve a kind of scale data from the offline customer acquisition. We think about it, just like Doctor mentioned, right now we are testing several different channels for the customer acquisition through the offline channel. Not only for the education centers with Baiyoudian. We think about it, we are now looking for the best solutions for the customer acquisition through the offline channel centers.
Thank you.
The next question comes from Jessie Xu with Nomura. Please go ahead.
Thank you. Thanks management for taking my question. We noticed that the revenue growth of smart devices has been very strong for the past few quarters. Should we expect the momentum to continue? On top of that, is there any opportunity for cross-selling with Youdao Premium Courses? Thanks.
Thanks, Jessie. I'll talk about the growth and Peng can talk about the cross-sell. Revenue growth of smart devices, it's looking very good. Q4 is a traditional strong quarter. Q1 numbers we are happy with. As I said in the prepared remarks, we have new products upcoming this year. We don't talk about actual new products before their launch. We do have new products and new category of products. We really think this year is the year that we have products serving people's different needs that's going to be released in this year. Different categories. The seasonality of the learning devices business is that normally you would see Q3 and Q4 being the strong quarters. Because Q3 is the beginning of the new learning year, new academic year.
Q4 is the e-commerce most strong quarter. These two quarters are the stronger quarters. Q1 and Q2 are relatively weaker. Obviously, start of the academic year is a very important time for the smart devices, for the learning devices business. I will look at Q3 as a pretty important quarter for that business. The team has a lot of ideas and a lot of projects going on. We think this is going to be an important and fruitful year for learning devices.
As for the cross-selling of our smart devices, we are updating the related apps on our smart devices. There will be more customer-friendly functions in our apps. We focus on the productivity and continuously update our existing products, such as the Dictionary product, which leads to good sale and better margins in the learning product segment.
In the fourth quarter, we shipped over almost 300,000 units of our dictionary series in Q1, up 200% growth year-over-year. For providing a better learning experience, we deliver an effective learning experience with integrated across our smart devices and learning apps. Especially, we enhance the synergy between our Dictionary app and Youdao Dictionary Pen during the period. The Dictionary Pen users may find their personal learning summary and the vocabulary notebook in their Youdao Dictionary app.
Thank you.
The next question comes from Charlotte Hui with HSBC. Please go ahead.
Hello, management. Thank you for taking my question and congratulations on a very strong quarter. I have just a small follow-up question regarding the regulation item. There are some news saying that the online education players are not allowed to offer classes at low costs. Is it a confirmed rule or just a rumor? How will this affect the strategy of increased courses to attract new users, and how will our summer promotion plan change according to this? Thank you.
Yeah. Regarding the selling courses below cost, we are having ongoing discussions with the authorities. By now, basically being conservative. We have actually, for the summer courses, we have reviewed the sales price for our courses and actually raised some of the prices of some of the courses. Obviously, we are awaiting clarification from the authorities on this issue and also other issues. We believe we will get them in some time. I think the important thing here is that the conversion funnels for acquiring new customers, the teams, as we have operated in this business for quite a long time, we have many choices in the way that we convert users from someone who's interested in getting a course to actually paying customers on our courses. We have many choices that we can choose one from the other.
We think as long as we get clear guidance from authority, our teams will have change that they need to apply to the conversion channel. That's true for the low-cost courses. That's also true for how long before course opens you can start selling those courses. Several issues here that's pretty important, but as long as we can get clear guidance, we should be okay.
Thank you. I have one more question regarding the tutoring business. I'm wondering, what is the revenue contribution percentage from non-subject tutoring? Yes, because I know that game of Go courses are very popular in Youdao. Just want to have a sense of non-subject tutoring.
For the non-subject tutoring, we think about it. Right now, as the doctor mentioned in the call, we have a very promising product, this Youdao Go program. For the big school order for the primary school students. I think for this business, we see a tremendous potential from the parents and the users, and for their demands, and after demands. We expect to develop more capability performance-based programs offered to the preschool kids or the young students in primary school. We think about that probably may be in different areas. We think about that will have more great potentials for us to produce besides the program existing, like the Youdao Kids program and actually the YW sheet program.
We know we have been started for this business for several years, we had the experience to know how to develop and also build up the kind of momentum for those programs for the kids and the young students. We think about we are in a great position for this business. Thank you.
Okay, thank you.
The next question comes from Linda Huang with Macquarie. Please go ahead.
Hi, management. I have one question. This is regarding for our gross billing, because for this quarter we saw that gross billing up by 56%. When I'm looking back for the several quarters after we go listed, I think this probably is the slowest growth for the gross billing. How should we think about this number? Is there any reason behind the slowdown for this gross billing? Whether we should worry about that implies that our growth likely to moderate for the coming quarters. Meanwhile, for the enrollment, we also see that this quarter, the enrollment up by almost 100%, but compared to in the previous quarters, it's almost up by 200%-300%.
That's also the other question I want to ask is that whether we need to think about the moderating trend and what should be the optimal, I should say, the growth estimation for this number going forward? Thank you.
Okay. The first is about for the total gross billing, indeed, we just gross a little bit moderate compared with the same period last year. That's also just like we explained in our results, in our calls, and because that's mixed by the adult and the kids off. If you just only go to the K-12 sectors, it still grow about 103.2% year-over-year. That's still in the relatively high growth rate, thinking of the scale of our business. In total, it just goes like this slowdown is because of the adult business only grow about double digits in the first quarter compared with the last same period last year. That's because of the impact of COVID-19 in the last year.
Regular gross billing for the adult business in the last Q1 is a little bit high base compared with, so that we just achieve only a double-digit growth for the adult business. Put together, you see about the total number combined with the Youdao Kids and adult that go to that double-digit numbers. You go back to see independently for the Youdao Kids and adult, you can see the Youdao Kids still in the very good grade growth momentum for our business. Go back to enrollments, Q1 it's just like I mentioned about in the last Q1, it's also whatever the business in the Youdao Kids and adult is being impacted by the COVID-19 in the last year. Although we are most likely in the last year, we benefited about the growth from through that impact with adult sessions.
For the Youdao Kids enrollment, we also beneficial through that. Yes, beneficial through that growth for the business in the last Q1. We think in this year, 100%, we think about this relatively still great momentum for growth. Also for the Q1, it's not really the big season for our customer acquisition in this momentum. We think about if you go back to see our growth rates about the Youdao Kids business in the last year from Q1 to Q4, you think about it also accelerates about growth rates compared with the same time the year before. We think about it, we will expect about more good numbers for the growth in the rest of the quarter in our expectation.
It still depends on the situation, whatever the surroundings, environment, and also including the regulation or the other issues probably potentially will be affect about the growth rate. In our expectation, we expect the growth rate for our business, and it will be acceleration by the first quarter in one year. Thank you.
That concludes the question and answer session. I would like to turn the conference back over to management for any closing remarks.
Yeah. Thank you once again for joining us today. If you have any further questions, please feel free to contact us at Youdao directly or reach out to TPG Investor Relations in China or the U.S. Have a great day.
The conference has now concluded. Thank you for attending today's presentation.