See the same ad enough times and you stop seeing it. Worse, you start resenting it. That decline in response is ad fatigue, and it hits performance campaigns harder than brand work because the metrics are immediate.

The first few exposures usually perform best. Click rates climb, then flatten, then fall. Frequency climbs the whole time, so cost per acquisition rises while return on spend drops. Media buyers watch for this curve and rotate creative before it bottoms out.

Signs fatigue has set in

• Falling click-through rates at steady spend
• Rising cost per click and cost per acquisition
• More negative comments and hidden posts
• Frequency above three or four per user

The fix is rarely more budget. New visuals, a different angle, a fresh offer, or simply resting the audience for a while. Sometimes the same message works again months later with an audience that has forgotten it.