Conversion Evidence Ledger

Conversion Evidence Ledger treats every landing page test as an accounting entry, not a creative experiment. Each cycle records the hypothesis, the traffic source, the sample size, the lift, and the resulting change in cost per acquisition, so a client retainer renewal rests on a documented chain rather than a single before-and-after screenshot. The framework matters because agencies increasingly sell against buyers who expect performance proof, and a page change that cannot be traced to a CAC movement is an anecdote. A practical entry looks like this: run a headline variant through a builder with native split testing such as Leadpages or Instapage, hold the ad set constant, and log the delta in cost per lead alongside the test window. Audit tooling can seed the hypothesis queue before spend begins; PageCritic returns a conversion score with seven sub-scores and three prioritized fixes, which gives the ledger a starting baseline instead of a guess.