Cohort analysis is a method that groups users based on shared characteristics or behaviors, then tracks how each group performs over time. For ecommerce, this typically means grouping customers by their first purchase month and measuring how they continue to buy.
Types of Cohorts
Acquisition cohorts group customers by when they first converted. January buyers form one cohort, February buyers another. This reveals whether recent customers behave differently than older ones and helps measure true retention rates.
Behavioral cohorts group customers by actions they take. Customers who used a discount code form one group, full-price buyers another. This helps identify which behaviors correlate with long-term value.
Key Retention Metrics
Cohort analysis answers questions that aggregate data cannot. What percentage of January customers made a second purchase? How does that compare to February customers?
Common metrics include repurchase rate by cohort, over time, by acquisition month, and days between orders. These reveal whether your customer base is improving or declining.
Ecommerce Applications
Track whether customers acquired during sales events have lower than organic customers. Measure if product changes improved retention for new cohorts. Identify the typical timeline for repeat purchases to time remarketing campaigns.
Businesses using cohort analysis report retention improvements up to 20% by tailoring strategies to specific customer groups.
GA4 Cohort Reports
GA4 includes built-in cohort exploration reports. Select a cohort dimension like first session date, then measure retention or revenue over subsequent periods. Custom segments let you create behavioral cohorts based on specific events.
