An example
An Acme Watches unboxing video starts at a 34% hook rate and a $36 CPA. Six weeks later it sits at 22% and $55, while a brand-new video in the same ad set opens at 33%. The audience still responds to fresh work. It is this one video that has worn out.
Why it matters
Every creative has a shelf life, and spending past it is one of the most common leaks in an ad account. Spotting it early means the replacement is ready before results slide. Many teams look closer when frequency passes 3 and CTR has dropped about 20% from its first weeks, but treat that as a rule of thumb that varies by account.
How to improve it
Track hook rate and CTR per creative over time, not just the account average. Keep a pipeline of new concepts so a replacement is ready, and try iterations of the tired ad, like a new opening on the same body, before dropping an idea that worked.