You cannot randomize a bad experience
Causal inferenceHardProblem. You want to know what a bad experience costs. The obvious comparison is retention among users who had one versus users who did not. A colleague says that gap is the answer. Is 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.