The ability to measure the additional impact or value of a specific marketing campaign or strategy. It is used to determine the incremental impact of a particular campaign or treatment on a specific metric, such as sales or conversions, relative to a control group that did not receive the campaign or treatment. Incrementality can be measured through different types of tests, such as A/B tests or lift studies. Measuring incrementality allows marketers to understand the true impact of their campaigns and strategies on business outcomes, and make more informed decisions about where to allocate marketing resources.