However, not all users are the same. When they first sign up to your site, new users may actually behave in different ways. Their behavior determines whether they will stick to your site or not. A more advanced version of cohort analysis is behavioral cohort analysis. The famous example of this is Facebook's realization, based on user research, that: if a new user adds 7 friends in the first 10 days of using Facebook, they will become an engaged user. Why is this type of analysis important? If you want to maximize engagement and retention, knowing what features / behaviors will make users stick can inform tremendously product building. In the case of Facebook, they changed their onboarding process to incentivize new users to add 7 friends in the first 10 days.
There are a number of companies that give you metrics based on user behavior (
Amplitude, for example). They offer advanced analytics that let you study user behavior in detail. However, if you want to start doing basic behavioral cohorts (for free!) you can use Google Analytics to obtain some good results. Here's how: