Cohort Analysis: Understanding Retention Over Time
Cohort analysis groups users by a shared characteristic — typically when they first used your product — and tracks how their behaviour changes over time. It is the most effective way to understand whether your product retains users, and whether retention is improving or deteriorating.
What a Cohort Analysis Reveals
- Whether users acquired in different periods retain at different rates (are recent cohorts performing better or worse than older ones?)
- The natural retention curve for your product — where users drop off and when they stabilise
- The impact of product changes on retention — did a feature release improve retention for cohorts acquired after it launched?
- Differences between acquisition channels — do users acquired through paid ads retain as well as organic users?
Reading a Cohort Retention Table
The classic cohort retention table shows each cohort (row = acquisition period) across time periods (columns = weeks/months since acquisition). Cell values show the percentage of users who were active in that period. A healthy product shows a retention curve that flattens — indicating a stable retained user base.
Tools for Cohort Analysis
- Mixpanel / Amplitude: Purpose-built for cohort and retention analysis
- GA4 Retention reports: Basic user retention cohort view
- Custom SQL: Full flexibility for complex cohort definitions using your data warehouse