Gem wager on a 7-day streak after a lesson: +14% day-7 retention
Commentary byLiftArchiveOur analysis, not theirsDuolingo added a step right after a lesson reward that invites learners to stake gems, its in-app currency, on keeping a 7-day streak, and day-7 retention rose 14%.
Duolingo ran this; case study by Growth.Design, which walks through the step in its Duolingo user retention teardown.
- Day-7 retention: +14% with the wager step, as reported by Growth.Design. More learners were still active a week later.
- Growth.Design does not say whether the 14% is a relative lift or percentage points, so read it as a direction and rough size, not a precise figure.
- No other metrics are shared, such as gem spending, lesson counts or longer-term retention.
The change
The variant adds a gem wager on a 7-day streak right after the lesson reward.
Simplified mockup drawn by LiftArchive from the shared screenshots.
Control
After finishing a lesson and getting the reward, the learner moved on through the normal lesson flow with no wager step.
Variant
Right after the lesson reward, the learner sees an offer to bet gems that they will practice for 7 days in a row. In the Growth.Design walkthrough the stake is 50 gems.
Why it likely won
Our reading of the result, not the practitioner's claim.
- The ask comes right after a reward, when the learner feels good and is most open to committing to more.
- Staking gems is a small investment. People tend to value and protect what they have put resources into, which is the sunk cost effect Growth.Design points to.
- The bet sets up a clear goal with a deadline, which gives the app a natural reason to remind the learner over the next days.
- The wager costs only virtual currency, so the downside of saying yes feels low, which likely keeps take-up high.
Caveats: Growth.Design reports the figure without sample size, test length, confidence or a definition of the metric, so the size of the lift can't be checked. It covers a single app with a mature streak and currency system.
Who ran it
Duolingo ran this test. Source: Growth.Design case study. The numbers are theirs; the summary and commentary on this page are ours.
How to run this test on your app
- Hypothesis
- If we offer users a chance to stake in-app currency on a 7-day streak right after they finish a session, then day-7 retention will rise because the stake and the clear goal give them a reason to come back each day.
- Primary metric
- Day-7 retention
- Guardrails
- Churn after a lost streak or lost wager
- Day-30 retention
- Paid conversion or purchases of in-app currency
- Who should test it
- Habit apps with a daily use loop and an existing in-app currency or streak, such as language, fitness, meditation or study apps. It probably won't work in apps used a few times a month, or where there is no currency people care about losing.
Questions
Does a wager only work if the app has a virtual currency?
The Duolingo version uses gems, so users risk something they earned in the app.
Without a currency you could stake a badge or streak protection, but that version hasn't been tested here.
Won't users who lose the bet quit?
They might. Duolingo's former Head of Growth has said losing a streak is a big reason people quit, so track churn among users who lose a wager, not just day-7 retention.
When should the wager be offered?
Duolingo shows it right after a lesson reward, when users have just succeeded.
Offering it at a cold moment, like app open, may get fewer takers.