Campaigns don’t die suddenly. They decay. Here’s how to read the signals.

How decay actually works

A campaign launches with novelty. Attention is high, engagement is strong, conversion is good. Then the audience encounters the campaign again. And again. The novelty premium erodes, and with it the emotional engagement that drove the initial response.

This is not a failure of the campaign. It’s the normal lifecycle of content in a competitive attention environment. The failure is in not detecting the decay early enough to act — either by refreshing the creative, adjusting the targeting, or pulling the campaign before it starts generating negative associations.

The half-life problem

Different campaign types have different half-lives. Brand campaigns built on emotional resonance decay slower than promotional campaigns built on offer mechanics. Content designed for discovery decays faster than content designed for consideration. Understanding the expected half-life of your content is the starting point for any decay-aware strategy.

The brands that make this calculation explicitly — building a decay curve into the campaign plan, not discovering it post-launch — make significantly fewer of the “why didn’t we pull this earlier” mistakes that most teams recognise in retrospect.

What to watch for

Engagement rate decline is the obvious signal, but it’s a lagging indicator. The earlier signals are in sentiment: the comments becoming more perfunctory, the shares declining before the impressions do, the organic mentions dropping off while paid distribution maintains reach.

For brand campaigns specifically, the signal to watch is brand perception — whether the campaign is still strengthening the intended associations or has moved into neutral or negative territory. That shift happens faster than most brand teams expect, and later than most media plans assume.

Building decay-awareness into your content strategy

Pre-plan refresh points. Build the next creative iteration before the first one launches, so you’re not responding to decay with a gap in the market. Establish clear decay thresholds — specific metrics that trigger a creative review, not just an optimisation discussion.

And read the sentiment signals, not just the performance metrics. A campaign that’s generating impressions but declining in brand equity is not performing. It’s just spending.