Incrementality
Incrementality is the part of a result that advertising caused: the sales that would not have happened without it, as opposed to the baseline.
Updated September 28, 2026
What does incremental mean, in marketing? Caused by the advertising: the difference between what happened with it and what would have happened without it. Incremental revenue expresses that effect in money, incremental sales in units or orders, and incremental lift as a percentage of the counterfactual outcome. That second number is a counterfactual nobody observes directly, so incrementality is always an estimate of a difference, with an interval, and the interval is part of the answer.
There are two ways to build the counterfactual. An experiment creates it on purpose, by withholding the advertising from a group that would have behaved like the rest: a geo-lift test does it by region, a holdout by user or customer. A media mix model estimates it from history, by separating the media from everything else that moved sales, and the experiments calibrate the model.
The definition matters because platform dashboards report attributed sales, not incremental ones: attribution overlaps across channels, counts customers who would have converted anyway, and stays high on saturated channels. Incrementality is measured at a spend level, on an outcome the business cares about; marginal incremental ROAS is the same idea read on the next euro. In the Media Planner, a measured result is tagged measured, next to the model’s figure tagged projected, and the plan shows both.
The incrementality pillar covers the three ways to measure it and how to read a result.