Answer Share Decay

Answer Share Decay treats citation frequency in AI answer engines as a perishable asset rather than a fixed ranking. Unlike a page that holds position for months, a cited answer can vanish within weeks as models retrain, sources rotate, and competitors publish fresher material. For agencies, this reframes AEO from a one-time setup into a recurring monitoring line item tied to retainer renewal. The decay curve is measurable: run a fixed set of 20 to 30 buyer-intent queries monthly through Perplexity, ChatGPT, and Google AI Overviews, then log which client domains get cited. HubSpot's 2026 State of AEO data shows most audits still rely on traditional SEO metrics, which miss this drift entirely. A client cited in September may be absent by November without any ranking change, and that gap is exactly what justifies a monthly answer-visibility retainer instead of a project fee.