How to spot it
Frequency over 3.5, CPM up 20%+ in 14 days on a stable audience, CTR down 25%+ in the same window, and CPA rising while spend holds flat. All four together is unambiguous; any two together is enough to investigate.
How to fix it
Rotate creative or refresh the audience. Forced calendar rotations kill scaling creatives prematurely; per-creative trajectory analysis is the better signal.
How Ripplux uses it
Ripplux watches every active creative for the four signals and emits healthy, watch, or fatigued. The Decisions page surfaces the verdict with a recommended action.