Incrementality - Proving Your Marketing Actually Works
Understanding the difference between correlation and causation in marketing
This is the most important chapter in this course.
Learn why incrementality is the most important concept in performance marketing
Up to this point, performance marketing can feel deceptively straightforward. If ads generate a positive ROAS, the logic suggests you should simply scale spend and expect results to compound.
But there is a more fundamental question that comes before scaling:
Is your advertising actually driving those results — or merely taking credit for them?
ROAS, CPA, and conversion metrics describe outcomes. They do not, on their own, explain why those outcomes occurred. Without answering that causal question, scaling can amplify spend without increasing impact.
This chapter introduces incrementality — the discipline of testing whether marketing activity changes behavior at all, rather than just measuring activity that would have happened anyway.