First-time Event

A first-time event is the first occasion on which a given user performs an event; it is the basis for measuring activation and for separating a new user from a repeat one.

Most events are repeats, but the first occurrence of an event for each user carries a different meaning: a customer's first purchase is not the same as their hundredth, and creating a project for the first time is often the 'aha moment' where the user grasps the product's value. So the first-time event is the backbone of activation and retention analysis; the rate at which new users reach that key event connects directly to growth. Detecting a first-time depends on one crucial thing: a stable user identity over time. If a user is seen as two people across devices or before and after login, the same event may be counted 'first-time' twice and the activation rate inflates. So the accuracy of a first-time event is only as good as identity merging.