WHY SEARCH ROAS DEPENDS ON PAID SOCIAL MORE THAN YOU THINK

Summary from the TLDR Marketing newsletter

Search ROAS often looks strong only because paid social is running alongside it, generating brand awareness that later surfaces as branded search queries search then gets credited for capturing. Last-click attribution can't see social impressions that never converted directly, creating a structural bias where search inherits demand it didn't create. The effect is delayed by four to eight weeks, so teams that cut social based on isolated ROAS comparisons often see search CPAs climb months later without connecting the two. Geo holdout tests and brand search volume tracking are the more reliable way to measure the actual cross-channel effect.