Creative fatigue as a decay curve: labelled teaching data, not a market law

Frequency can rise while IPM falls without proving the asset is ‘dead’. This lab fits a simple decay to the reader’s own points so the assumption is visible.

Define the calculation before using it

Enter baseline IPM at frequency one, observed IPM at a later frequency, and that later frequency. Compute a constant per-step multiplier that connects the two points. Apply it only as a scenario, not as a forecast.

Work through the synthetic example

A baseline IPM of 12 at frequency 1 and 6 at frequency 4 implies a per-step multiplier of 0.7937. That describes those two teaching points. It does not establish a genre benchmark or an optimal refresh day.

Use the artifact and preserve its assumptions

Open the editable calculator to change the inputs and inspect the sensitivity view. The CSV records synthetic inputs and expected outputs; the JSON fixture keeps the equations available for reproduction. These calculations have been checked against the stated example. No measured campaign data is included.

The sensitivity rows vary only ipmN by 20% below and above the entered value. They are scenarios, not confidence limits or a forecast distribution. A row outside the model’s constraints is labelled rather than turned into a plausible-looking result.

Evidence and limits

Google documents frequency as impressions per user over a period, and capping as a control. It does not publish a universal IPM decay function for game ads. See About frequency capping, especially “Frequency capping”.

Two points cannot identify a true decay process. Auction mix, audience exhaustion and creative concept changes are out of scope.

Background: Anatomy of a creative that scaled, then died and The creative brief is a hypothesis document. These existing articles provide context; the present calculation does not verify every archived claim.

Draft prepared 19 September 2026. Synthetic teaching example; human editorial and specialist review pending. No actual campaign outcome or recommended industry default is claimed.