Ad fatigue is what happens when an audience has seen the same creative enough times that it stops earning attention. CTR drops, CPC rises, CPA inflates — sometimes within a single week of scaling. It's not a bid problem or a targeting problem; it's a creative problem.
Signals
- CTR drops 30%+ vs 7-day median while CPM is flat
- Frequency (impressions per user) above 4 with declining incremental conversions
- Comments shifting from positive to neutral (or hostile) on the same ad
- Suddenly higher CPA on a previously-working ad with no audience or bid change
How to fight it
- Refresh creative every 2-3 weeks at minimum on cold prospecting
- Run 4-6 creative variants per ad set so the algorithm has options
- Rotate hook structure — if a question hook is winning, test a stat hook + a testimonial hook
- Use frequency caps to prevent over-serving the same user
- Expand audience definition to bring in fresh users — broader interests, larger lookalike