Every ad decays. The audience sees it enough times that it stops registering, the cost creeps up, and the response curve bends down. This is fatigue, and it is not a sign the ad was bad; it is a sign it worked and then ran its course. The teams that win treat fatigue as a scheduled event, not a surprise, and they have the next ad ready before the current one dies.
Watch the leading indicators, not just the lagging ones. Rising frequency, falling click-through rate on a previously strong ad, and climbing cost-per-result are the early warning that an ad is tiring, often weeks before the conversion number visibly drops. By the time cost-per-acquisition spikes, you have already overspent on a dying ad. Build a simple rhythm of refreshing creative on a cadence rather than waiting for the cliff.
Refresh is not the same as reinvent. Most of the time the angle still works; only the execution has worn out. A new hook, a new visual, a different format carrying the same argument can reset the clock for far less effort than starting from a blank brief. Keep your proven angles in a library and re-dress them. Reinvent only when the angle itself has stopped converting across every execution you try.
This is why the single-hero-ad strategy is fragile. One ad, however good, is a single point of failure that will fatigue and take your whole channel down with it. A rolling roster of three to five live ads per audience, with fresh ones entering as tired ones exit, keeps the channel stable and gives you a constant stream of clean comparisons to learn from.
