Signal Half-Life

Signal Half-Life is the shelf life of any competitor SEO or AI-visibility data point before it stops being defensible in a client conversation. Rankings, citation sources, and AI answer mentions shift weekly, so a dashboard screenshot from three weeks ago is a historical artifact, not a current claim. Agencies that treat intelligence as a perishable input build a refresh cadence into the retainer: monthly re-runs for stable keyword sets, weekly for AI answer monitoring where models update without notice. The framework matters because it reframes tool spend as a subscription to freshness rather than a one-time audit. One concrete example: Google's AI content contribution pilot reportedly paid some publishers under 0.1% of ad revenue, a figure that will move as the program changes, so any client deck citing it needs a date stamp and a re-check before the next quarterly review.