Cohort Analysis

Cohort analysis is a way of studying a group of customers who share a starting point, such as everyone who signed up in the same month, and following that group over time. Instead of one big average that hides the detail, it shows whether newer customers behave better or worse than earlier ones.

It is like tracking each year's intake at a school separately, so you can see whether this year's class is doing better than last year's rather than lumping them all together. This matters because it reveals whether a recent change actually improved things, which a single headline number can easily disguise.