Definition
Frequency rises, click-through falls, costs climb - the audience has memorized your ad and stopped seeing it. Fatigue is inevitable; the only variables are how fast you detect it and how quickly fresh creative replaces dying ads.
Why it matters
Weekly creative testing exists precisely because fatigue compounds silently - accounts that ship new angles monthly outperform template-refreshers by wide margins.
Benchmarks
Watch frequency >3 weekly on prospecting; refresh before CTR drops 20%
All glossary terms