First Time User Experience (aka New User Experience / NUX) is inordinately critical in the lifetime of a user; if a user doesn’t ‘get’ the proposition and reach a moment of delight — or at least appreciation — during their first few minutes using a freshly-installed mobile app, the session will probably be their last.
The majority of user churn occurs in the first few days. Cohort decay graphs all take fundamentally the same shape, regardless of the app. New user onboarding efforts should aim to flatten out the curve at a higher retention rate. If this can be achieved, compound growth gains follow.