Good morning, everyone, and welcome to the presentation of Rightmove's results for the first half of twenty twenty one. My name is Peter Brooks Johnson, and I'm joined by Alison Dolan, our CFO. I'm going to talk through the highlights of the year. Alison is going to go through the more detailed financials and then I'm going to spend a little more time giving you more color on the housing market and our strategic developments. In the first half of this year, we've delivered financially and more importantly, strategically, which sets us up for the future.
In 2020, COVID-nineteen upended the lives of everyone across the UK. And the last time we met, there was much questioning about how long it would take Rightmove to regain its momentum as the housing market emerged from lockdown. The right move network effect has emerged stronger than ever as Home Hunters continue to turn to right move first and customers invest more in our digital solutions. To demonstrate how we've emerged from the shadow of 2020, I have compared our performance versus June 2019. The 2020 numbers are here too, so if you wish, you can calculate that our revenue is up 58% on a year ago, but I think that's a level of flattery we don't need.
Site traffic in the 1st 6 months of the year was again a record, with an average of 1 point 7,000,000,000 minutes per month being spent on the platform. The busy property market has created very different dynamics in our Agency and New Homes customer bases. Agency customers are very busy and focused on winning the right to sell properties efficiently. Our Agency business continues to grow back from a year ago with a further 130 branches added in the first half of the year. Many of our new homes customers are forward sold until early 2022 and therefore we've seen a drop in new homes developments and developers easing back on marketing as they have less to sell.
In total, ARPA is up GBP 86 on June 2019, with the Agency ARPA growth of GBP 107 driven by a good mix of price and product. We've been flattered a little with some of the one off cost savings in the first half, which Alison will detail later. As promised at the full year, we have been returning the extra cash we built up in 2020 with GBP 128,000,000 returned and consistent with our long established policy, we are increasing our interim dividend in line with EPS to 3p. Beyond our KPIs, we've made much strategic progress this year. Rightmove's purpose is to make home moving easier in the UK.
We'll satisfy our purpose and drive growth through innovation. Our strategy has 3 reinforcing segments. Firstly, we are the place Home Hunters turn to and return to first. This in turn makes us the UK's property platform, which delivers unparalleled ROI for our customers. And then we are in a unique position to help both customers and Home Hunters By making the process more digital and also create new revenue opportunities for us.
This slide gives you some examples of our strategic delivery in the 1st part of the year. We continue to innovate in our heartland of property advertising and tools for property professionals. We generate return for our customers in 4 distinct ways. We help them save time. We have products which help them actively grow their market share.
We help them market more efficiently by using the power of by far the largest audience of Home Hunters in the UK and we help them grow new revenue streams. For example, The secure video viewings platform we introduced last year has saved our agency customers nearly 6000 days in wasted time arranging and performing viewings in the last year. We continue to innovate and deliver new efficient marketing products to our customers. I previewed the advanced development listing back in February. It launched in April and we've been really pleased by the performance.
It's delivering a lead uplift to developers of around 30%. Developers also seem pleased with it with over 20% of developments now listing using the new product. And to demonstrate the value of this innovation to us, given its trajectory, this product is likely to add £3,000,000 revenue to new homes next year During a time when developers are reducing their marketing spend. As we previously talked about, we're experimenting with demystifying online conditional auctions on-site and this is to help agents grow a new revenue stream. The first provider is now live with 4 more in the process of integration.
And I'll talk more about the benefits of our unrivaled data asset in Opportunity Manager later. We believe there's much opportunity in making the Home moving process more efficient by being more digital. I'll talk more about the digital tenant journey and what we've learned from our mortgage experiment later. There's much excitement for the future, but this is all built on our strong position today. Before I give a little more color on our strategic position, I'll hand over to Alison to talk more about the numbers in detail.
Thanks, Peter. Good morning, everyone. The first half of twenty twenty one shows a pleasing continuation of the growth seen in 2019. As Peter just explained, our revenue product and ARPA growth in the first half of this year is best illustrated by a comparison to 2019, the last full year of no pandemic related disruption. So, compared against the half year to June 2019, Revenue has increased by £6,000,000 or 4 percent, comprising a £4,800,000 increase in agency revenues and a GBP 3,700,000 increase in the other operating segment, what we call our breadth businesses, all partially offset £2,500,000 reduction in new homes revenues.
The agency growth of £4,800,000 was driven by Strong product purchase and package upgrades on both 2019 2020 as agents competed to win vendor mandates in this strong market. In fact, product revenue as a percentage of overall agency revenue has increased by almost 5 percentage points since 2019 and is currently at 57% of total agency revenues. Upgrades to our premium package Optimizer 2020 contributed particularly strongly to revenue growth in the 6 months of 2021. New Homes revenues continue to reflect The challenges of a forward sold market where developers are selling off plan are struggling to build at the pace necessary to meet current demand and therefore have less of a need to market new properties. In other revenues, with the exception of overseas, which continues to be impacted By travel restrictions, each of the 3rd party advertising, commercial and data services businesses has grown relative to June 2019 And each is up by about £1,000,000 on that date.
Mortgages revenue is now £2,000,000 The product launched late in 2019, but is up by about £250,000 on June 2020. Year to date ARPA at the 30th June was up 8% on 2019 And at £11.63 is our highest ARPA to date. Within that, Agency ARPA was up over 11%, An uplift of £107 driven in part, as I mentioned earlier, by product upgrades, particularly to OPTI 2020. The period overall saw a big uplift in the purchase of incremental digital products, both as package upgrades and on an alacarte basis. New Homes ARPA was slightly down on 2019 by 1.25%, reflecting the current market.
The new homes market tends to run countercyclical to the agency market. This is a dynamic we have seen before and seen recover, but we do expect the current situation to remain consistent for the remainder of twenty twenty one and into the first half of next year. The 6 month trailing ARPA has been shown here also as it shows the clear line of continual growth in ARPA since 2019, looking through all of the business disruption of 2020. The charts on this slide show the drivers of ARPA since June 2019. Of the Agency 11% uplift, 45% or £49 is due to price increases over the 2 year period.
Included in this is £9 of ARPA from the 6 months to June 2021, in which we brought forward a number of price increases which had been scheduled for later in the year. A further 36%, £38 was driven by package upgrades. In this 6 month period alone, over 800 customers upgraded to Optimizer 2020, almost 100 of which upgraded directly from the basic essential package. The average monthly revenue uplift Per customer upgrading to Opti 2020 is just under £300 a month. 16% of our independent customer base We're on this top package at the end of June, up from 9% in December 2020, and we have continued to upgrade additional customers to our top package throughout July.
Included within this £38 is revenue from customers continuing to purchase additional products On an alacarte basis, beyond their package thresholds, as they compete to win vendor mandates in a strong market like this one. Revenue from local valuation alert alone, for example, is up 30% since 2019 and featured property has seen a similar uplift. And then finally, customers choosing to take incremental products in lieu of a price rise on their core subscription contributed a further 19% or £20. It's always a very pleasing outcome when this happens. Conversations that start as a price increase end up with a package upgrade and we generally find that customers retain the additional products that they have selected in this way.
We've also shown the drivers of the new homes ARPA, which are slightly different to Agency. New Homes ARPA is down £17 over the same period, but shown here are the gross movements within ARPA, where we have seen good growth from greater product purchase in particular, which alone has contributed £42 of ARPA since June 2019. As with Agency, the proportion of new homes revenues from product has also increased since 2019 by 3 percentage points in this case. Price increases have contributed GBP 24 of ARPA in the same period. However, Digital marketing campaigns are where we have seen new homes developers choose to reduce their marketing spend, which has eroded the product and pricing growth With an £83 reduction to give an overall drop of £17 Digital marketing is discretionary spend above subscription listings, and it is typically where we would see the developers cutting spend in a market as strong as the current one.
So although it has eroded the gains in product upgrades and pricing, those latter two provide a strong base for growth Relative to June 2020, Operating costs have increased by 5 percent or CHF 1,800,000 to CHF 35,200,000 largely driven by recruitment for our product development and sales teams. As we indicated when we reported 2020's full year results, This investment is partly in response to the recruitment pause during 2020 and partly to reflect continued investment in product and website On recruitment, we have been recruiting throughout the first half, but in the heart of lockdown, it proved more difficult to do at Scale and pace that we have been hoping to achieve, and so the pace of acceleration in headcount costs has been lower than we thought it might be at the beginning of the year. Although we are now running at the right pace, headcount cost in the first half has been weighted towards the final months and therefore the run rate of costs in the second half will be higher. Once we've completed the recruitment catch up, 1 in every 3 of our employees will work in product development and a further 1 third in sales, which is about what one might expect from a digital business such as ours.
Technology costs, which include all the costs associated with running both our sites and the business itself, So hosting, licenses, traffic costs, etcetera, have increased marginally, up by 300,000 all associated with the increase in traffic to our sites over the period. No meaningful number of employees have returned to the office yet, Which has meant that staff related cost savings have been available for longer than we expected, CHF 1,300,000 in this reporting period. We are now reasonably confident that we will have everyone back in the office 3 days a week from September and these costs will return closer to normal. Overall, costs are back to their steady state of just under 25% of revenues, which is where they were in 2019 and where we anticipate We will end the current year. It is also broadly where we expect them to remain for 2022.
All of this has resulted in underlying operating profit of £117,000,000 up 5% on 2019 And an associated operating margin of 78%. As I've mentioned already, the second half of the year will see a higher run rate of costs, Reduced savings as more staff return to the office and obviously no repeat of the Van Mildred provision release. So the full year margin will fall by a few percentage points. We do, however, expect it to be ahead of the 71% level we discussed at last year's full year results given the strong revenue performance in the first half. On cash, operational cash generation remains strong at 106%, a level similar to last year.
All of the cash generated in the half, along with £30,000,000 of cash generated in 2020, was returned to shareholders with the resumption of the share buyback program and the payment of 20 twenty's final dividend in May. We ended the half with £68,000,000 of surplus cash, down from £97,000,000 in December and much closer to our expected final year balance of about £50,000,000 As Peter mentioned earlier, we are also announcing a 2021 interim a term dividend of 3p, which will be paid in October and which will amount to about £26,000,000 We will also be continuing the share buyback program throughout the second half. On the P and L, We've shown the impact of the various adjustments, share based payments and the release of the van Milder provision, the underlying operating profit UP CHF 117,000,000 and the associated operating margin of 78%, to which I referred earlier, exclude the share based payments, but include the provision release. The change in the balance sheet is driven almost entirely by the lower cash balance. Working capital metrics remain consistent during the period and there has been no increase in bad debt.
We continue to pay our suppliers on the same prompt terms as previously with average days payable for trade creditors remaining at around 20 days. Now, I mentioned at the full year results that we would on one element of ESG at each of our reporting periods. And today, I'll update on the S element, the social element. Rightmove sets out to make our company a great place to work, where people can bring their full selves to work, where they are helped to develop and progress, and to feel supported and mentored when they face challenges. So for our management team, social is about creating the right conditions and encouraging the right behaviors to facilitate this, ensuring not just that obstacles for our people to develop are removed, but that opportunities for progression are available and that developmental training and mentoring support are accessible at the right times throughout people's careers with us.
During the pandemic, supporting people who have struggled was an acute need. But beyond that, Ongoing measures to support the well-being of our people have always been important, as has the sense that when our people look around the company, They can see people like them and feel a sense of inclusion. There are three areas of focus for us, therefore, when it comes to employee support: Well-being, Training and Development and Gender and Ethnicity. During the pandemic, we launched A well-being, personal and professional development program called How We Thrive, giving all employees access to multiple health and well-being workshops, Support Networks and Therapeutic Coaches. And an arrangement with our insurer has made available confidential private sessions with a mental health coach, which have been accessed by over 20% of our staff in the past 6 months.
Our 16 Mental Health First Aiders Triage mental health issues that are brought to them using non judgmental conversations either to resolve an issue or to guide those involved towards external support. In appointing them, we have also sought to remove any perceived stigma and provide an inclusive environment where people can openly seek support. One of the biggest jumps people make in their careers is the move From team member to manager. At Rightmove, this can often mean a move to managing people who were previously peers, which can be quite daunting if done with no training. So management training and ongoing development is a key area of focus for us.
Managers are trained across a 6 month period on how to provide and receive ongoing feedback and how to have open conversations about performance, Pay, development needs and behaviors. Over 5000 hours of this training were delivered in 2020 alone. Getting the gender and ethnicity balances right has always been important at Rightmove. But this year, we have actively delayed a number of senior hires Until we could find females who were right for the role, and we will do more of that as we seek to maintain equal female representation to close our gender pay GAAP. The mean of which is currently at 24% and the median at 33%.
It is a GAAP that we are determined to close. In the meantime, we are proud of our Gender Balance Board with 3 non exec directors from ethnic minority backgrounds, exceeding the Parker reviews recommendations. And then lastly, supporting the communities in which we operate, namely Milton Keynes, London and Newcastle, and supporting causes which are important to us, such as promoting the study of STEM subjects, particularly for Girls, has been part of our agenda for the last few years. Of note, this year, we have signed a partnership with Generating Genius, whereby our employees provide a mentoring network to the participants of the Black Women Into Tech program. We awarded a university scholarship for someone to study a STEM subject to degree level and we donated computers to needy schools in Milton Keynes during the pandemic.
There is a lot more to cover, but I hope this has given you a flavor of the social issues that are important to us as a company and the sort of culture we try to foster is Rightmove to ensure that our people are proud of the company they work for. Part of the remuneration for us as Executive Directors requires that over 90% of our people think that Rightmove is a great place to work. And I'm happy to report that 93% of them thought so in December 2020. We also, of course, Want our culture to be a reason for new people to come to work with us. So that's it for me.
I will now hand back to Peter to take you through the strategic
Thank you, Alison. I'll start off by briefly covering what happened in the housing market in the first half of the year. The frenetic activity towards the end of last year and early this has now started to manifest in transactions being completed, as you can see in the top chart. In fact, according to HMRC, there were more transactions completed in the first half of twenty twenty one than in any 6 month period since before 2,006. For many of our Agency customers, the high number of transactions and a slightly higher commission rate has enabled them to rebuild their balance sheet after the turbulence of 2020.
The big question many have been asking is what will happen now the stamp duty holiday is starting to taker in England? As a reminder, In England, at the end of June, we saw the stamp duty free threshold for all transactions being cut from £500,000 to £250,000 In September, this extra relief will be withdrawn and once again, only first time buyers will be stamped duty free up to GBP 300,000 It's impossible to determine how much of the market has been driven by the stamp duty holiday, but our proprietary data, shown on the bottom left, gives calls for cautious optimism post the withdrawal of the holiday. This graph shows the level of demand, the number of sales being agreed and the number of new listings, all indexed versus 2019. The grey line is our forward looking measure of demand. This is the number of people actively looking to buy in the market.
And looking at our most up to date data, despite the end of the holiday, in July demand is still 30% higher than the same time in 2019. And this demand is feeding through into sales agreed. The orange line is the number of sales we believe are being agreed. And at the moment, that's typically 4 to 6 months ahead of the property completion, putting deals agreed now beyond the end of the September deadline. Again, the latest data in July shows that sales agreed are exactly the same as 2019.
To give more comfort, we've only seen a slightly high number of transactions fall through this year, which given the significant increase in deals agreed is very positive. In fact, as July has progressed, the fall through rate has returned to the same level as 2019. This is consistent with surveys we've run, which suggest that only around 4% of buyers would run would pull out of a transaction if they fail to meet the stamp duty deadline. Most people are moving to find a home which meets their needs. They don't see it as an asset.
I spoke back in February about the lack of new stock coming to market. You can see from the teal line, this trend has improved a little bit Good. You can see from the teal line, this trend has improved a little since then with the relaxing of lockdown and possibly the return to school. But we're still seeing new listing levels around 10% down. The supply and demand imbalance is impacting the market in a few different ways.
Prices are being driven up. The average asking price is nearly 7% higher than the start of the year. And the property market is becoming more efficient. Typically, only around a half of properties listed will sell. This has risen to nearly 70% recently and that's supporting the increased rate of sales being agreed.
New agent formation is slower than one might expect at this point in the cycle as, Of course, a new agent has to win all their new stock to begin trading. New homes developers are also experiencing record demand with 20% more development selling out in the first half of this year compared to 2019. Taken together, As you might imagine, it would be advantageous for Rightmove if the end of the stamp duty holiday did cool the market a little bit. So now I'll talk more about Rightmove. I'll look at each of the following in turn.
I'll lead with Home Hunters, our package and product sales and the number of customers. I'll then wrap up by looking at some of the innovations we've delivered. So starting with our lead with Home Hunters. Time spent on Rightmove was up nearly 60% last year. And if you needed a demonstration of the instinctive place that Home Hunters turn to, We recorded a new busiest day ever on the 3rd March, the day of the budget, with over 70,000,000 minutes spent on the platform in a single day.
You can see from the Comscore chart that our market share of time has nudged up despite quite a lot of marketing activity from our competitors. I think it's worth just delighting on the Comscore chart for a moment. Firstly, you'll notice that Comscore has yet to begin tracking Booming. We also use similar web tracking, whilst perhaps not as comprehensive, it has the benefit of being more real time. SimilarWeb shows Booming's share of time to be less than 1%.
Secondly, you may remember the Comscore methodology change back in February 2019. Dean. Comscore have alerted us to another upcoming change, which I expect will reverse some of that step up. So for those of you who follow Comscore, Don't be alarmed if you see that happen in the next 6 months. But all of this adds up to one way we deliver value to our customers quality leads, which were up over 50% year on year.
In order to win sellers, agents are aiming to differentiate themselves from their competition. The strong sales market has focused agents on winning the right to sell a home more effectively and more efficiently. I'm particularly pleased with the sales range of Optimizer 2020. The graph on the bottom right compares the package numbers of Optimizer 2020 with its popular predecessor Optimizer 2015. Since launch, it has consistently outperformed the previous package with COVID only slowing it down for a few months.
The right hand end of the graph graphically demonstrates the value our customers see in Optimizer 2020 to help them succeed with record numbers of customers upgrading during the first half of this year and that sales momentum has continued in July. The pie chart shows which package those customers were upgrading from and as ever the majority are upgrading from optimiser 2015, but nearly a third have upgraded from our middle, enhanced package, having seen the benefits of our products and wanting to make the most of their marketing budget. For now, our focus remains on optimiser 2020, but enhanced is still playing a very important role in our package ladder. And that's one of the design features of our package structure. Customers can upgrade through it as they feel more confident.
And as they upgrade, they get even more value. And as Alison discussed, those upgrades could either come as a result of a pricing conversation or as a result of a customer request. I'm content with how we structured our pricing conversations this year and given their success, we've pulled forward some of the conversations we were intending to have later in the year. So far, we've spoken to around twice as many customers as we had intended to and we've added some more activity in the second half to get a head start on the 2022 plan. So moving on to customer numbers.
Demonstrating the underlying value of our proposition to agents in both slower and Stronger Markets. We've had the lowest number of first half levers since 2014, which has driven our retention rates to the highest it's ever been. I think it's also testament to support we gave customers last year in the depths of lockdown. However, as I mentioned earlier, New agent formation has been slower than might have been expected as the lack of new stock coming to market is making it very difficult for new agents to start up. In addition, the higher sales efficiency means there are fewer instructions which end up moving agents, meaning there are less 2nd bites of the cherry for agents who miss out on an instruction first time.
I think there are a number of existing agents waiting for slightly more stock to come to market before committing to a new branch too. For the second half, I expect branch numbers to continue a gradual rise unless we see a sustained growth in new listing numbers. In new homes, as you will have heard us say many times, developers are already forward sold well into next year. It's simply a story of reduced supply an increased demand having to work through the system. The number of new homes listed was 15% down in the first half compared to the same period in 2019 as the difficulty constructing against the backdrop of social distancing reduced output.
And on the flip side, we've seen over 50% more demand for new homes. In terms of number of new homes developer companies advertising with us, that hasn't changed. So, I fully expect the number of developments will rise when we move out of this particular supply and demand imbalance. Looking forward for the next 6 months, I think we'll continue to see a drop in development numbers for most of the second half As the new home construction start numbers are still down over 20% in the Q1 compared to 2019, and as I showed earlier, we don't see any significant drop in demand. So how are we innovating to help agents and developers succeed in this market?
I thought I'd show you one of the products which our customers are using to win. Our unrivaled knowledge of Home Hunters allows us to help agents uncover the potential sellers within the pool of potential buyers they already know. And using our data, we can predict when the seller is ready to consider instructing an agent. BrightView is in a unique position as 2 thirds of the people sending leads have yet to select an agent to sell their home. Opportunity Manager is exclusively available to optimise the 2020 customers.
It uses a real time algorithm to help the agents prioritize their work with a simple color code. In stock constrained markets like this, It's even more important for agents to be able to talk to potential sellers before their competition. Opportunity Manager correctly identified around a 3rd of the properties which came to market in the 1st 6 months of the year, typically giving the agents who use the product a month head start over their competition. Of course, we can only highlight the opportunity. The agent still has to win the instruction.
But to give a sense of scale, That's a commission pool of over £500,000,000 Looking a little further out, we're going to make home moving easy by helping Home Hunters be more transaction ready and by being more digital. As I've talked about in previous presentations, we've been focused on improving the process of renting for the last few years. We believe because of our unique position in the market with more people searching for rental properties than anywhere else, We're the only company to be able to truly change the rental process for the better from end to end. We've just delivered the first element of the second phase of the plan. We've enabled one click reference ordering from Rightmove Plus.
When a tenant has requested an appointment via Rightmove, an agent can request a referenced from us via Rightmove Plus and the property and tenant details are pre completed in the reference order. The agent can also see the status of all their current references from Rightmove Plus with the obvious efficiency benefits. This streamlined flow from Lead to Keys is what we'll continue to focus on in the coming months. There's more integration planned in the second half of the year to enable the tenant and appointment details to feed into the agent CRM systems. And we're also working on the contract part of the process and expect to launch that early next year.
The digital insurance flow for tenants who've passed referencing has just been launched. You may remember we've been relying on the telephone up until now to make sure we could learn the basics as fast as possible. We've got a lot to learn around the digital conversion for tenants' insurance As a key part of the service is helping tenants understand that they're not covered by their landlord's insurance. This need for confidence has been backed up by a notable number of tenants going through the digital flow and then getting in contact with us directly to purchase. And all of this activity has been supported by rebranding Van Mildert to Rightmove.
We think our trusted brand will bring more confidence to tenants in what is clearly a difficult process. Referencing is key to the digital rental journey. It's both the moment when a tenant finally gets a reasonable level of certainty they will be able to move in and it's also the doorway to a number of new opportunities for us. We know that timing is crucially important when selling ancillary products like contents insurance, broadband and energy and referencing is the best indicator of a tenant when a tenant wants to buy these products. Not only does referencing generate revenue in its own right, This timing indicator may well give us an advantage when marketing solutions to tenants and landlords.
Today, for every reference we complete, We generate just over GBP 4 of revenue from tenants and landlords, taking into account the current attach rate. We're early in the journey of scaling this revenue opportunity, so I wouldn't want you to get carried away just yet. This is the first time we've created a revenue stream from consumers. I see this as becoming meaningful perhaps in a couple of years' time and we're working on 3 levers to grow this revenue. Firstly, increasing the number of references we complete.
We only process around 7% of references in the market. Referencing is currently a competitive industry with little differentiation. We believe that by continuing our integration and simplification, we will be able to create a best in class reference which is simple for tenant and agent, which balances speed and accuracy. In the last year, we've increased our referencing speed by 20%. It's pleasing to see that our attach rate for insurance is climbing and that's the indication of our strategy of working hard on offering the right product in the right way.
But we can see that we've got more work to do, particularly with our new digital flow. And finally, we can offer more services to tenants. We're still in the early stages of learning with TV and broadband as you can see from the chart. And beyond that, I'm sure you can all think of things that we might be able to successfully offer to tenants. And in doing this, we're not only creating new revenue stream for ourselves, we're making home moving easier for tenants and much more efficient for our agents.
We're also working on making home moving easier for our buyers. Earlier, I said I'd share some of the learnings from our mortgage experiments and what we found won't surprise anyone who's been searching for a property and who needs a mortgage. Not only can the process be daunting, Home Hunters tell us it significantly adds to the stress of finding your next home. The fundamental reason is that as someone looking for a home, It isn't until very late in the process you become certain that you'll actually get a mortgage and therefore that you'll actually be able to buy the home you're looking at. If one looks at the current flow, shown on the top, you can see that most home movers only really start to be confident that they can get a mortgage but they point at the point they want to make an offer on the home they've chosen.
That's the 4th step along. That's pretty inefficient. It It can also be pretty upsetting as many Home Movers will have pretty much set their hearts on the property by that stage. Whilst there's much activity in making mortgage application more digital, we are in the unique position to bring the mortgage earlier in the home buying flow. Looking at the flow we're building on the bottom, not only do we believe we can increase the Home Mover's confidence earlier in the process, probably before the viewing, By offering easy, personalised, lender backed decisions in principle, we also think we can remove some wasteful steps too.
So far, our work gives us confidence in our approach. By working on our tools, content and placement, we've doubled the number of leads we sent to our lender partner in the last year. And those leads are of better quality with 3 times as many receiving a lender issued decision in principle as a year ago. But again, we've much to do and much to learn in this space. We will continue to focus on the process up to decision in principle with more innovation in bringing together mortgage and property search Tools and Joining Up, Helpful Content.
By doing this, we will increase the number of leads and the conversion rate to decision in principle, which in itself will lead to more which is being written. We've got much to do and much ambition. But let's bring it back to 2021 and wrap up with the outlook. The network effects of the Hartwell business are stronger than ever with record traffic and leads. At the moment, the property market is busier than it's been for a long time.
Whilst the level of impact to the end of the stamp duty holiday will have is hard to predict, The indicators we have give cause for optimism that demand we see in the market is founded on a desire to move rather than just a holiday. Agents continue to recognize the value in our unrivaled audience and products with the strong ARPA growth being driven by a combination of pricing changes and agents upgrading package to grow their business. Looking forward, we see that momentum continuing in the second half and we are planning to bring forward some 2022 pricing changes into this year. This won't impact our revenue this year, but will mean we hit the ground running in 'twenty two. Mindful of the lack of stock, I think it's prudent to assume we'll see a small growth in agency branch numbers over the rest of the year.
And equally, I think the very good conditions will continue for new homes developers. So for the rest of the year, I'd expect the number of developments on-site to fall as they set out. And as you've seen, there's no slowdown in our ambition to make home moving easier or indeed our long term outlook.