Cohort Retention
The proportion of a defined group that remains active, subscribed or retained over successive periods after a shared starting event.
Cohort retention shows whether customers acquired at different times or through different channels keep using and paying, which reveals product-market fit, onboarding quality and the real value of acquisition spend.
A SaaS team builds a monthly cohort table in GA4: of 800 users who signed up in March, 320 are still active in month three, a 40% retention rate, compared with 31% for January signups before onboarding changes.
Results depend on the definition of active and the return criteria chosen. Small cohorts are noisy, and changes in pricing, tracking or acquisition mix can explain differences that look like product improvements.
Users are grouped by a shared starting event, such as signup month, and tracked over periods since that event. Retention for period N equals cohort members active or retained in period N divided by the cohort's starting size. Classic retention counts activity in that exact period; rolling or unbounded retention counts activity in that period or later. Results are shown as cohort tables or curves.
Data Engineering, Experience Design
Google Analytics Help — Cohort exploration — https://support.google.com/analytics/answer/9670133; Mixpanel Docs — Retention — https://docs.mixpanel.com/docs/reports/retention