Retention Rate

Retention rate measures the percentage of users still active at a given point after their first use, typically checked at Day 1, Day 7, and Day 30 milestones.

D1 retention (still active the day after signup/install) is heavily influenced by onboarding quality and first-session experience; D30 retention is a much better long-term product-health signal but takes a full month to observe for any given cohort, which is why teams watch D1 and D7 as faster leading indicators while waiting for D30 data to mature.

The shape of a retention curve over time matters more than any single day's number — see retention curve. A curve that keeps declining toward zero indicates the product hasn't found a stable core user base; a curve that flattens out (the "smile curve") at some percentage above zero indicates a genuine retained core, even if the flattening point is low.