Rewarded opt-in rate decay across a 14-day cohort (labelled synthetic)

Fatigue in hybrid and IAA-heavy titles often shows first as a falling rewarded opt-in rate, before CPI moves. AdMob rewarded ads define the format as ads that reward users with in-app items for interacting with video, playable or survey ads, with an OnUserEarnedRewardListener when the reward is earned. That is a product definition, not a retention benchmark.

This lab uses labelled synthetic cohort inputs. It is a method worksheet, not a claim about your live title.

Define the metric before using it

• Eligible session: session where a rewarded placement was offered (studio event).
• Opt-in: user started the rewarded experience (studio event; not the same as reward grant).
• Opt-in rate (day d): opt-ins on cohort day d ÷ eligible sessions on day d.
• Decay (d0→d14): 1 − (rate_d14 ÷ rate_d0), when rate_d0 > 0.

Map reward grants and impression revenue separately via your mediation/MMP path (for example AppsFlyer’s af_ad_revenue event in the ad revenue attribution guide). Do not treat reward grant as IAP.

Synthetic worked example

Decay d0→d14 = 1 − (0.240 / 0.420) = 0.4286 (42.86%).

Facts versus limits

Download the CSV. Replace synthetic rows with your export; keep the equations fixed.

Research checked 20 September 2026. Local draft; human editorial review pending. Author null.