Many products mark activation when a single checkbox fires. That number looks decisive and rarely explains churn in week two.
Map a short sequence: first useful action, second return, and the behaviour that predicts paid or retained use. Instrument each step with the same identity rules.
When a step disappears after a redesign, retention charts panic. An activation diagnostic usually finds a silent tracking break before a product crisis.
Write the sequence on one page and review it monthly. That page is worth more than another funnel colour palette.