Diagnose Why Facebook Lite Retains Users Worse Than the Main Facebook App

You are a product manager at Meta. Facebook offers two apps: the standard app (often called "Facebook Blue") and Facebook Lite, a lighter version built for regions where internet bandwidth is low. The data shows that user retention is lower on Facebook Lite than on the standard app. Investigate why: how you would check the gap, what could explain it, how you would test those explanations, and what you would do with the answer. ```hint Compare like with like The two apps were built for different people in different conditions. Before blaming either app, think about what makes a straight comparison of their retention unfair, and how you would make it fair. ``` ### Clarifying Questions - How is retention measured here: the share of new users still active after a set number of days, or the share of last month's active users who are active this month? - Is retention counted per app or per person? If someone moves from Lite to the standard app, or uses both, is that person counted as lost from Lite? - Is the gap measured across all users worldwide, or within the same countries, network types and phone models? - Has the gap always existed, or has it opened or widened recently? ### What a Strong Answer Covers - A precise retention definition, and checks that the two apps' numbers are measured the same way (offline logging, switching between apps, duplicate or fake accounts). - Separating differences in who uses each app (country, network, phone, tenure) from a real gap within comparable segments. - Locating when in the user lifecycle the gap opens, using cohort retention curves and new-user funnels. - Hypotheses across user circumstances, app experience, technical reliability and network effects, each paired with the evidence or test that would confirm it. - Prioritized next steps and a better metric for judging Lite going forward. ### Follow-up Questions - Within the same country, network type and phone model, the gap disappears. Is there still a problem to solve, and whose is it? - Many users who "leave" Lite turn up on the standard app after buying a new phone. How would you change the metric and the team's goal? - Someone proposes adding more video features to Lite to raise engagement. How would you test this without breaking what Lite is for?