21 August 2025 · Attribution
Attribution windows when StoreKit and Play Billing disagree
A single ROAS number across both stores is a mood. A metric contract is a sentence two teams can initial.
Marketing wants one return figure. The stores offer two legal regimes, two device graphs, two notions of “pending,” and two ideas of when a click may still claim a receipt. In-app purchase analytics that averages them into a blended ROAS tile is not simplifying. It is erasing the disagreement so the weekly meeting can finish on time.
What actually differs
StoreKit’s world still leans on Apple’s privacy constraints, SKAd-style conversion values where they apply, and receipt fields that do not carry your MMP click id unless you put it there. Play Billing has acknowledgement windows, alternative billing experiments in some markets, and a purchase token that does not mean what an iOS original transaction id means. Click-to-receipt time on one store is not transferable to the other. Pretending otherwise is how “iOS is just more expensive CPIs” becomes a personality, not a measurement.
Write two windows, then a third only if you must
The Attribution Atelier asks teams to publish an iOS contract and an Android contract before anyone mentions blend. Each contract states: click source, allowed lookback, what counts as a qualifying receipt (paid, not trial start), how refunds claw back credit, and who owns the number. A third “company rollup” is allowed only as a clearly labelled average of the two contracts — never as a third independent truth.
Pending is not paid
Play pending purchases will inflate a 24-hour ROAS if you credit them. They will deflate it later if you do not claw back. Pick a rule, write it, and stop arguing in Slack with screenshots from different hours. In-app purchase analytics is mostly the courage to freeze a definition.
MMPs do not dissolve the stores
Your measurement partner can stitch clicks. It cannot make Apple and Google share a graph. If two MMPs disagree, do not run a bake-off on blended ROAS. Compare them inside one store, one window, one receipt definition. That bake-off is slower. It is also the only one that means anything.
This essay is the public shadow of a closed studio. Dates for Attribution Atelier go through contact. The wider map of signals sits on the IAP Signal Map.