Creative
Ad fatigue
Decline in CTR/CVR as the same ad over-exposes the same audience.
Ad fatigue is the falling CTR/CVR pattern as a single ad creative reaches the same users repeatedly. Fatigue starts to bite at 3–5 average daily impressions per user; severe at 10+. Diagnosed by rising frequency + falling CTR over 2–3 weeks. Solution: rotate fresh creatives, expand audience pool, or pause and rest the audience. Native ads fatigue faster than display because the user is making an active click decision.
Example
Outbrain campaign at $400/day shows CTR dropping from 0.62% to 0.34% over 18 days at fixed audience size — operator launches 4 new creatives; CTR snaps back to 0.58% within 5 days.