Definition
Hold out a region or audience from advertising, compare results against exposed groups, and the difference is true incremental lift. It is the only method that answers 'did the ad cause this?' rather than 'did the ad touch this?'.
Why it matters
Platforms claim credit for existing demand; incrementality testing prices that claim honestly - mature programs calibrate platform-reported numbers against periodic tests.
Benchmarks
Run quarterly at minimum on your largest channel
All glossary terms