Glossary
Retention analysis
The study of how many users keep returning to and engaging with a product after their first use.
Also called: user retention
Retention analysis measures how many users continue to come back and use a product over time after they first sign up or install it. It is the inverse view of churn rate: instead of counting who left, it counts who stayed.
The standard technique is cohort analysis: users are grouped by the period in which they were acquired, then tracked to see what share return, or perform a key action again, at set intervals such as day 1, day 7, and day 30. Retention rate for an interval is users active in that period / original cohort size. The resulting retention curve—not a single point on it—is what tells you whether a product has staying power, since curves that flatten out indicate a stable core user base.
Retention is one of the strongest signals of product-market fit and feeds directly into customer lifetime value estimates. Two common pitfalls: definitions of "active" or "return" vary widely (opening the app versus completing a core action), and it's easy to focus only on already-retained users and lose sight of the engagement rate and experience of everyone else who didn't come back.
Last reviewed September 19, 2026