Attribution
Geo-Lift Test
An incrementality testing method that uses matched geographic regions as test and control groups. One region receives ads while a statistically similar region does not. Particularly useful when user-level holdout tests aren't feasible (e.g., due to iOS restrictions or cross-device complexity). Requires careful market matching and enough regional volume to be statistically meaningful. Works well for measuring the incremental impact of channel-level spend changes like pausing Meta in one region while keeping it active in another.
Why it matters
It is how you test a channel that cannot be split at the user level, which now includes most of the major platforms post-ATT.
In practice
Match test and control regions on pre-period revenue trend rather than population. A control that was not tracking your test region before the test cannot tell you what happened during it.
Related terms