Your MMM says email ROI is huge — why might the model be lying? — Pinterest Marketing Data Science Data Scientist Interview

Your MMM says email ROI is huge — why might the model be lying?

Causal inferenceHard

Problem. Your marketing mix model reports that email has a very high ROI, so the team wants to pour budget into it. Why might the MMM be misleading, and how would you pressure-test it?

Before you reveal: say your answer out loud, as if you were in the real interview — get your reasoning across clearly first. There is no single correct answer: reading what the interviewer is really after and defending your own thinking is what makes an answer strong.