How To Keep Your Users | Startup School

TL;DR

Cohort retention—tracking what fraction of new users keep using your product over time—is the single best quantitative way to know if you've made something people want. The only thing that matters is whether your cohort retention curves get flat, not the absolute retention percentage; flat curves allow you to accumulate users over time.

Key insights

• Cohort retention tracks individual groups of new users (cohorts) over time, rather than mixing all users together.
• The three necessary definitions: how to isolate cohorts (typically by first-use week or month), what action counts as "active" (should correlate with real value, e.g., viewing a photo full screen), an
• In a triangle chart, each row is a cohort; the diagonal line across months represents total active users in a given calendar month.