Duolingo founder on the key to solving retention “The way we solved [retention] was just through trial and error,” Duolingo founder Luis Von Ahn explains. “By now, some of us have some intuition about what is good for gamification, but the reality is that most of it is just trial and error.” He continues: “In the history of Duolingo, we have run 16,000 A/B tests. Each one of those is trying to figure out if we change these little things — “should this button be red or blue?” — to try to get you to come back. And it’s these 16,000 A/B tests that have made our retention outstanding. At this point our user engagement is starting to get comparable to social networks.” Video source: @StanfordGSB (2025)

6.9.25 — @larryvc on to talk about why capital efficiency still wins, and: • The Chewy example: $50M in, $3B+ out • Why CapEx is back and how to measure it like marketing • What founders should learn from AI-native businesses scaling with 10 people

🚨 Data drop! Our team @a16z published benchmarks on revenue growth for AI startups, from our proprietary dataset The median B2B co is going 0 -> $2.1M ARR in year 1, while the median B2C co is going $0 -> $4.2M (yes, consumer startups are growing revenue faster 🤯)