Playbook: Migrate Between MMPs Without Losing 3 Months of Data

Playbook: Migrate Between MMPs Without Losing 3 Months of Data

Switching from Adjust to AppsFlyer (or back)? Run dual-tracking, don't rip and replace:
— Stand up the new SDK alongside the old one for a 14-day overlap window
— Map every event name 1:1 — af_purchase vs Revenue naming will silently break dashboards
— Re-register all SKAN ad network IDs; missing one kills iOS attribution for that partner
— Rebuild deep link routing and test every Universal Link / App Link path
— Compare install + event counts daily during overlap; expect 2-5% variance, investigate over 10%
— Migrate audiences and cohorts last, only after counts reconcile
— Notify every ad network of the new MMP before you cut over postbacks

✓ Overlap window proves parity before you trust the new tool
✓ Catches event-mapping gaps while the old data still exists
✗ Two SDKs briefly inflate app size and init time
✗ Network re-registration can take partners days to confirm

Verdict: Never hard-cut an MMP — 14-day overlap is the difference between a clean migration and a quarter of blind spending.
Best for: Teams replacing their attribution stack on a live app.