AD CREATIVE FATIGUE: WHAT IT IS AND HOW TO PREVENT IT

Summary from the TLDR Marketing newsletter

Creative fatigue happens when Meta detects declining results due to overexposure. It's not inevitable and is often caused by small, fixable issues like one-ad sets or narrow placements. It is easy to prevent it by using Advantage+ placements, offering five or more text and headline variations, and customizing creative by placement. Fatigue sets in when people see the same thing too many times in similar spots. The more variation built in the campaign, the longer it can stay efficient without causing fatigue.