Your question is Measure Campaign Impact on Behavior. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
You work on a consumer beverage marketing team that is running a campaign and seeing an immediate sales bump. Stakeholders want to know whether the campaign actually changed customer behavior or only pulled purchases forward.
How would you measure whether the campaign changed behavior in a durable way, rather than just driving short-term sales? What would you treat as the primary signal, and how would you avoid being misled by a temporary lift?