Designing a Retention Measurement Framework for Facebook Timeline

You are the product manager who owns Facebook's Timeline: the profile surface where a person's own posts, photos, life events and profile details are collected, and where friends come to look at them. Explain how you would measure the Timeline's retention: what counts as a retained user, which metrics you would track, and how you would read them. ```hint Define a return Before naming any metric, decide what "coming back to Timeline" means for each kind of person who uses it, and how often a healthy user would naturally come back. ``` ### Clarifying Questions - Whose retention matters here: people who keep their own Timeline up to date, people who look at other people's Timelines, or both? - Why is retention being measured now: an ongoing health dashboard, judging a recent Timeline change, or explaining a decline someone has already noticed? - Does a passing glance at a profile count as a return, or only a visit where the person reads, reacts or adds something? - Should the metrics cover Timeline alone, or also show how Timeline use relates to time spent elsewhere in Facebook? ### What a Strong Answer Covers - What Timeline is for and why its retention matters to Facebook as a whole - The distinct groups who use Timeline, and an explicit decision on whose return the metric tracks - A precise definition of a retained user: the qualifying action, the time window and the cohort, each justified by how often people naturally use Timeline - A primary retention metric with supporting and guardrail metrics, keeping retention distinct from engagement depth - How the numbers would be segmented and interpreted, including movements caused by something other than Timeline itself ### Follow-up Questions - If Timeline retention dropped while overall Facebook retention held steady, how would you work out why? - How would you tell whether a change that brings people back to Timeline more often is drawing that time away from other parts of Facebook rather than adding to it? - Which of your metrics would you use to judge an A/B test of a Timeline redesign, and why might a short test mislead you?