How Incrementality Works
It is estimated with experiments or models that compare exposed activity with a credible counterfactual, such as a randomized holdout or matched market.
A Simple Example
If an exposed group produces 1,100 purchases and a comparable control implies 1,000 would have happened anyway, the estimated incremental lift is 100 purchases.
Why Incrementality Matters
Incrementality answers the budget question attribution cannot: what did the advertising actually add?
Common Misreading
Platform-attributed revenue is not automatically incremental. Branded search, retargeting and existing customers can make reported returns look stronger than causal returns.