Glossary · Business Analytics

Cohort Analysis

also: cohort economics · retention curve

Definition

Cohort analysis groups users by a shared origin event (acquisition month, first purchase, signup source) and tracks behavior over time for each group. It separates true retention from the compositional distortion caused by new-user dilution, and is the foundational unit of analysis for subscription economics.

Aggregate retention metrics mix users at different lifecycle stages, creating misleading trends. Cohort analysis slices by origin and follows each cohort's retention curve. The curve's asymptote — whether it flattens above zero or decays to zero — is the empirical signature of product-market fit. Cohort unit economics (CAC, LTV, payback) should always be computed at the cohort level, never the rolled-up aggregate.

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