Moving the ATT prompt after first value lifted opt-in from 28% to 49%

Moving the ATT prompt after first value lifted opt-in from 28% to 49%
An app fired Apple's ATT prompt on first launch, cold. Opt-in sat at 28%, starving deterministic iOS attribution.

They added a pre-permission priming screen and delayed the system prompt until after the user completed onboarding and saw first value (a saved result).

Result across 120k new users:
— ATT opt-in rose to 49%
— deterministic (IDFA) attribution coverage nearly doubled, sharpening every downstream model

✓ Opt-in timing is the single biggest iOS measurement lever
✓ Priming screen set context without dark patterns
✗ Delayed prompt means early sessions stay SKAN-only
✗ Gains vary by category — utility beat games here

Verdict: never prompt ATT cold — earn the opt-in after first value.
Best for: iOS apps with low opt-in and SKAN-heavy reporting.