Do AI citations decay over time?

Yes — citation decay is a real phenomenon predicted by the GEO Stack's Layer 5 framework. AI retrieval systems continuously update their corpus as new content is published. A page that earns a citation rate in month one will see that rate erode over time as fresher, newer sources compete for the same retrieval slot. Scrunch's March 2026 research found an average 4.5-week half-life across 3.5 million citation events. The GEO Lab's E014 experiment is testing this finding independently with documented methodology.

Which AI platform holds citations longest?

According to Scrunch's March 2026 research, Perplexity holds citations longest at approximately 5.8 weeks before 50% decay. Google AI surfaces cluster in the middle at 4.3–4.8 weeks. ChatGPT cycles through sources fastest at approximately 3.4 weeks. Platform choice matters more than industry vertical in determining citation persistence under the Scrunch data. These figures need independent verification — Scrunch has not published their measurement methodology.

What does citation decay mean for GEO strategy?

Citation decay means that earning a citation is the beginning of a maintenance process, not the end of an optimisation project. The practical implications: monitor citation rate monthly rather than treating it as a one-time measurement, prioritise freshness interventions on highest-citation pages before decay begins, and weight Perplexity citations more heavily when allocating resources because they persist approximately 70% longer than ChatGPT citations under the Scrunch data.

What is The GEO Lab testing against the Scrunch finding?

Two experiments. E014 runs the 30-check protocol monthly across 10 core queries from April through September 2026, measuring whether citation rate accumulates and decays in a pattern consistent with the 4.5-week half-life finding. E019 tests whether a targeted statistics update on pages with stale data resets the decay curve — the specific intervention the Scrunch framework implies should work. Both sets of results will be published in the GEO Log as they come in.

Should I update my content every 4.5 weeks based on this finding?

No. Artificial freshening — cosmetic updates to justify a timestamp change — is a documented Google spam signal risk and is explicitly excluded from the GEO Stack's freshness protocol. The Scrunch finding justifies substantive content maintenance on a rolling basis: updating statistics with current equivalents, adding new findings as they emerge, and refreshing sections where the evidence base has changed. It does not justify manufacturing false freshness signals on a mechanical schedule.

Scrunch Found a 4.5-Week Citation Half-Life. I Am Testing Whether It Holds.

18 min read

27 Mar 2026

Artur Ferreira

Data & Experiments

Share this post:

← The GEO Log