Incrementality

Incrementality measures how many conversions marketing actually caused, as opposed to conversions that would have happened anyway. It is the difference between correlation (this ad was seen before a purchase) and causation (this ad created the purchase).

How it works

Incrementality is measured with controlled experiments: holdout tests where a matched audience or region sees no ads, geo tests comparing markets with and without spend, and platform lift studies. The gap in conversions between exposed and holdout groups is the true incremental effect. Branded search and retargeting typically show the biggest gap between platform-reported and incremental results, because they intercept demand that already existed.

Why it matters

Attribution reports reward channels that show up near conversions; incrementality reveals which channels create them. Budgets reallocated on incremental evidence routinely move spend away from flattering channels toward ones that actually grow revenue. Learn more about our marketing attribution services.