If you run a company or a website,
cohort analysis is a great way to understand engagement and retention of your users. For example, how many of your users who signed up in June went back to your site in July? The chart below, for example, shows that
33.36% of all users who signed up on Month 0, came back to the site on Month 1. Google Analytics
recently added cohort analysis to the set of metrics that they offer to their users, so that you can generate retention curves like the one below on the fly. It is still in Beta, but it allows you to understand user retention over time, especially if you use Google Analytics with
User ID view, that is: you track data of signed up users with accounts.