An incrementality test that turns advertising on or changes its weight in some geographic markets and not others, then compares outcomes. Geo tests work without any user-level data, which makes them the standard method for measuring channels that cannot run user holdouts, such as TV, out-of-home, or a whole platform. Google's open-source GeoLift and Meta's GeoLift package are the common tools.
Related terms
Used in The Signal
Cite this entry:
Agency Echelon. "Geo Experiment." Agency Echelon Reference, reviewed September 2026. https://agencyechelon.com/reference/glossary/geo-experiment/