Thank you, John T., and good afternoon, everyone.
It is an honor to reconnect with you as Nextdoor’s CEO. Today, I have the same feelings of excitement and possibility as I did when we created this company 14 years ago. Nextdoor has certainly grown a lot since then, but I am confident that our best times are ahead.
We had a productive Q1, but before I get into those details, I'd like to briefly discuss how we're thinking philosophically and practically about taking Nextdoor to the next level.
In Silicon Valley, there is a commonly held belief that companies benefit when their founders return. I believe this is due to the value of the Founder's Mentality, a phenomenon explored by Bain Partners, Chris Zook and James Allen in their book of the same name. They argue that founders possess a set of attitudes and behaviors that is one of the most undervalued secrets of business success. This is the mindset that we plan to instill in Nextdoor.
We are technologists, and we believe that our greatest value comes from innovative product that delights users and customers. Yet we have the humility to admit that while the potential of our product is incredible, the current implementation today is just not where it needs to be. We're going to fix that and a Founder's Mentality is going to push us to do so. This means unwavering focus, an obsession on the details and complete ownership of and accountability for results.
Innovation for us starts with our core expertise of building community on a local level, which is an exceptionally difficult problem. We use this expertise to build an engaged consumer audience. And this audience attracts customers, who enable us to drive robust financial results.
Getting this virtuous circle right will unlock the full potential of the business. It is not easy and it definitely won't happen overnight, but we know the formula is successful. It's what enabled the creation of Nextdoor in the first place. I'm excited to talk more about building innovative products in the months and quarters ahead, but for now let's move on to Q1.
We've had a promising start to the year and continuation of our recent momentum. In Q1, organic Verified Neighbor growth again hit a new high. Weekly Active Users, or WAU, grew to 43.4 million, up 2% year-over-year and 4% sequentially, and engagement remains strong.
Also in Q1, we saw 17 percentage points of year-over-year adjusted EBITDA margin improvement demonstrating our commitment to driving efficiencies and improving productivity. We've now raised our full year adjusted EBITDA guidance and are on track to generate positive free cash flow in Q4, a full year ahead of schedule. We gain strength from our cash position, including our ability to repurchase shares, which we think remain attractively priced at their current level.
Our advertising platform is showing good progress. As of the end of Q1, 100% of our self-serve customers, which include SMBs and about half of our mid-market customers, are using Nextdoor Ads Manager to onboard and manage campaigns, and benefiting from improved ad delivery and performance on the Nextdoor Ad Server. These emerging capabilities have started to drive revenue growth and reduced the number of first party repeat ads delivered by 70%, real progress that we expect will continue as we began migrating our managed enterprise and our remaining mid-market customers later this year.
Among mid-market advertisers using self-serve, our increased capabilities allowed us to grow new logos by more than 50% year-over-year in Q1, increased average spend and deepen relationships with new advertising agencies. Our approach is clearly resonating with these advertisers.
Now it wouldn't be a proper earnings call these days without some mention of artificial intelligence. We've spoken before about how we've used generative AI via our Kindness Reminder to help users write positive posts. We've also added this technology to our Nextdoor Ads Manager to help businesses write ad copy. But we believe that our potential in AI is much larger than what we've built so far. Nextdoor has proprietary data, a local LLM and consumer distribution at scale, all fully owned and under the same roof. This makes us a kind of self-sufficient AI test kitchen, with all the needed ingredients in place as we seek to leverage this technology in new and valuable ways over time.
Before closing my remarks, I want to share some exciting news about our Board of Directors. We are pleased to announce 3 new additions, all founder, CEOs who have proven product chops, experience operating at scale and significant expertise in leading successful technology companies. Our new directors are Marissa Mayer, Founder, CEO of Sunshine and former CEO of Yahoo; Niraj Shah, Founder, CEO of Wayfair; and Robert Hohman, Founding CEO and Chairman of Glassdoor.
We are thrilled for them to join our journey to build Nextdoor into the definitive consumer Internet service in local. I'm realistic about our challenges, and we have a lot of work ahead of us, but we're optimistic about the road ahead. With that, I'll turn it over to our CFO, Matt Anderson.