Watch time is up but sends are down — is it a real win?

Decide from resultsHard

Problem. A Reels ranking experiment lifts watch time +4% (significant), but sends per reach (DM shares) fell −3%. The team wants to ship on watch time. What's your call?

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.

Interview tips

Strong-answer signal: explaining why sends guard against shallow watch-time gains, treating sends as a guardrail, and diagnosing the content mix before deciding. Common trap: shipping on the watch-time headline and dismissing the sends drop as noise without considering its higher variance.

A/B Test & Causal Inference Questions0 / 220
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