Why Your Free Users Are Your Real Growth Engine – Cem Kansu, Duolingo CPO

“And it actually generated some revenue, even though very small.”

“We learned that users really cared about their streak, and a good percentage of our users are willing to pay a dollar or two to repair their broken streak.”

“Hence, our first test, and honestly even today, that's our only ad placement, is after you've completed a lesson, we show you an ad. Not during, not before, but always after, because we believe that doesn't interrupt your learning.”

“And when you looked at our community's complaint volume, if you quantify that, for example, per a million DAUs, how many ad complaints are there or add negative reviews, however you want to count that, versus other topics?”

“We blocked all those categories, like if it's gambling, even if it's games that look kind of sketchy, pick your category.”

“So we have eight Duolingo characters on Duolingo that you see, introduces the ad.”

“The decision logic is mostly now controlled by ML actually, but the ML uses various signals that is trying to figure out LTV maximization at its core”

“But we do way more like three month, six month holdouts on things that we know have different short, or we assume will have short to long term effects that might be different.”

“"You can buy an ad free month of Duolingo. So for 30 days, we'll turn off the ads, but it's a one-time purchase."”

“So we wrote a line there that was the thing that users were telling us, which is support Duolingo in its mission of free education.”

“Having free trials is one. I actually, as a PM, I resisted free trials for a long time. I assumed it would completely flop.”

“We even have designed pages which communicate, "Hey, this is a seven day free trial. On day five we're going to send you a notification to see if you still want your subscription." And this has performed well in AB tests”

“And then we tried, "Try for 0.00." Weirdly, that is the string that, I think, hacks your brain to really grock that button is entirely free.”

“We decided to integrate the hearts mechanic with our subscription and said, "Hey, if you subscribe, you actually get unlimited hearts." That was a big turning point because turns out a lot of users don't want to practice old content.”

“We tested it. We tested giving it for free and compared it to a B condition or a control condition where it is part of Max.”

“The other one is just the business realities of growing a separate app is extremely expensive.”

“It had this one massive problem, which is no one wanted to do it. It was really scary.”