Naomi Gleit

Was on Facebook's original growth team that pioneered the '7 friends in 10 days' metric, making her one of the few people alive who was in the room when the most famous activation metric in tech was created. Their core argument: Find the behavioral proxy that correlates with long-term retention, then ruthlessly optimize for it. Facebook's '7 friends in 10 days' was not a single magic number -- it was a point on a retention curve. The evidence is specific: Facebook used growth accounting to discover retention was the biggest lever, then identified friending as the key behavioral proxy. Furthermore, the new user experience (upload photo, find friends) was built specifically to drive the activation metric. In 2009, the growth team stopped all roadmap work for pure data instrumentation, which became the foundation for all subsequent optimization. In Naomi Gleit's own words: "Seven friends in 10 days was a thing. 10 friends in 14 days was also a thing. They're the same thing, they're just different points on a retention curve." (Explaining the legendary Facebook activation metric and how multiple thresholds pointed to the same underlying pattern.)

Longest-serving Meta executive after Zuckerberg, was on the founding growth team that invented the modern playbook for data-driven product growth -- the '7 friends in 10 days' framework that became the template for an entire generation of growth teams. Their core argument: Strongly data-driven and product-driven. Pioneered the approach of using data and experimentation as the primary growth engine, replacing traditional marketing-led growth. The evidence is specific: Facebook growth team stopped all roadmap work in January 2009 to focus exclusively on data instrumentation. Furthermore, 7 friends in 10 days (or 10 in 14) -- even the original team is not sure which was first, suggesting the specific number mattered less than the shared goal. Community translation product: instead of hiring professional translators, built a product for users to translate in-line (data-driven product approach to a traditionally non-product problem). In Naomi Gleit's own words: "What the growth team really pioneered was being data-driven and product-driven, especially in an area that was historically more of a business function. The insight that we had is actually the product is the biggest lever to drive growth." (Summarizing the growth team's core innovation.)

One of Facebook's earliest employees and a pioneer of the growth team model that reshaped how Silicon Valley thinks about product-led growth. Spent nearly two decades building the playbook that every growth team now copies. Their core argument: Retention cohort curves flattening is the ultimate behavioral proof of PMF. Facebook's growth team pioneered growth accounting: net growth = new users - stale users + resurrected users. The evidence is specific: Facebook's growth team was composed of engineers and PMs, not marketers, instrumenting every step of the user journey. Furthermore, the '7 friends in 10 days' and '10 friends in 14 days' metrics were equivalent points on the same retention curve. Gleit compares Facebook favorably to Airbnb, suggesting both had PMF so strong that growth teams may have been incremental. In Naomi Gleit's own words: "What we found was the churn in resurrection lines were actually much larger than the new user line, which implied to us that retention and driving those two lines was actually our biggest lever to drive net growth." (The insight that shifted Facebook from acquisition to retention focus.)

As Meta's longest-serving executive after Zuckerberg (employee #29, 19+ years), Gleit helped build the legendary Facebook growth team that pioneered data-driven product growth and invented frameworks like the activation metric (7 friends in 10 days) now used across the industry. Their core argument: Data instrumentation first, then research -- 'I guess when you can know'. The evidence is specific: Facebook growth team stopped all product roadmap work in January 2009 for pure data instrumentation. Furthermore, the 7 friends in 10 days (or 10 friends in 14 days) activation metric became the North Star for retention. Growth accounting framework revealed that churn and resurrection lines were larger than new user acquisition. In Naomi Gleit's own words: "In 2009 in January, we basically stopped doing anything on our roadmap except data instrumentation. And that's when we instrumented every step of the registration flow, instrumented every step of the new user onboarding experience." (Describing Facebook's radical decision to pause product work for data.)