Incrementality Testing
Experiments that measure the true causal impact of marketing by comparing to a control group.
Definition
Incrementality testing measures the actual causal impact of marketing activities by comparing outcomes between exposed and unexposed control groups. Unlike attribution that tracks who converted after seeing ads, incrementality testing reveals whether those conversions would have happened anyway.
This approach provides the most accurate measure of marketing's true contribution, revealing which activities drive additional business versus those that merely reach people who would have converted regardless. Incrementality testing has become essential as brands question whether their marketing is actually effective.
Why It Matters
Many marketing activities appear successful in attribution models but actually drive little incremental business. Incrementality testing reveals the truth about what's actually working versus what's just taking credit.
Understanding incrementality helps you invest in activities that truly drive growth rather than those that just look good in dashboards.
Examples in Practice
A DTC brand runs geo holdout tests and discovers that half their retargeting spend targets customers who would purchase anyway.
An enterprise software company uses incrementality testing to prove that sponsorships drive real pipeline beyond brand visibility.
A subscription service measures incrementality on paid social and reallocates budget from low-incrementality to high-incrementality campaigns.