Creative fatigue - when an ad stops working on the people it already reached

Creative fatigue is the decay in an ad's performance caused by repeated exposure to the same audience, rather than by anything wrong with the ad. The signature is a metric drift, not a cliff: frequency climbs, click-through rate slides, cost per acquisition rises, and the creative that carried the account for six weeks starts losing to a worse ad that nobody has seen yet. The fix is a new creative, not a new bid strategy. Widening the audience buys time by finding people who have not seen it; nothing but a new creative resets the people who have.

How to Read It

• Frequency rising while click-through rate falls is fatigue; both falling together is usually an audience or delivery change.
• Cost per acquisition drifting up over days, with conversion rate on the landing page flat, points at the creative, not the funnel.
• A fresh variant of the same concept that immediately beats the incumbent confirms fatigue; one that does not means the concept is spent, not the execution.

Worked Example

An ad runs 21 days. Days 1–7 it holds a 1.9% click-through rate at frequency 1.4. By day 21 frequency is 4.2 and click-through rate is 1.1%, a 42% decline with the landing page untouched. Swapping in a new hook on the same body restores the rate to 1.7% within two days, which tells you the concept still works and only the opening had been seen too many times.

The Other Side of Fatigue: What Survives

Fatigue is why an ad that is still running after weeks is interesting. Admetra watches the same ads day after day and scores age in two opposite ways, because "is this catching on?" and "did this survive?" are different questions. On the early-signal surface, being new is only a tie-breaker and freshness decays fast. On the evergreen surface, survival is the whole point and an ad still live after a month has earned most of the curve.