Incrementality
Also called: Incremental lift, Causal lift
Incrementality is the portion of an outcome that would not have happened without the action. It is measured against a randomised control, not inferred from attribution, and it is routinely far smaller than the numbers a last-touch report shows.
How it is calculated
Incremental revenue = Treated group revenue - Holdout revenue (per customer, scaled)
Report a confidence interval. A point estimate without one cannot support a budget decision.
Why it matters for ARPU
Incremental ARPU is the only version of the number that survives scrutiny, and it is the currency Markin reports in.
Related terms
Holdout groupA holdout is a randomly selected set of customers deliberately excluded from an action, kept as the counterfactual.Uplift modelAn uplift model estimates the change in outcome caused by treating a customer, rather than the outcome itself.ExperimentAn experiment is a controlled release of a candidate action against a randomised holdout, sized in advance so the result can distinguish a real effect from noise.A/B testAn A/B test randomly assigns customers to two or more variants and compares a pre-declared metric between them.