Activation Event

An activation event is the specific in-product action a team treats as the line between a user who merely signed up and a user who has reached real value.

Choosing this event is empirical rather than a matter of taste: early behaviours are compared against later retention, and the behaviour that separates users who stay from users who leave becomes the candidate. The most common mistake is picking a mandatory step in the signup flow, such as email verification; almost everyone passes it, so it distinguishes nobody and the rate it produces only looks healthy. It differs from the aha moment, which is the user's subjective realisation, while the activation event is the countable stand-in for that realisation; some tools call the same thing a critical event. An activation event always comes with a time window, because without one every user eventually activates.