Sizing daily shopping users across Facebook, Instagram, WhatsApp and Messenger

As a product manager at Meta, estimate how many people use Meta's apps for e-commerce on a typical day. State what you count as e-commerce use, label your assumptions, show your arithmetic, and check whether the result is plausible. ```hint Pin down the action first Before multiplying anything, decide which actions count as shopping and in which places across the apps they happen. Size each place separately, and remember that one person can show up in more than one. ``` ### Clarifying Questions - Is the estimate global, and does it cover every Meta app (Facebook, Instagram, WhatsApp, Messenger) or only one of them? - What counts as using an app for e-commerce: buying, browsing listings, tapping a shopping ad, or messaging a business about a purchase? Does merely seeing a shopping ad count? - Should sellers and businesses be counted along with shoppers? - Should the answer be distinct people on an average day, rather than the number of shopping actions? ### What a Strong Answer Covers - A precise, defensible definition of e-commerce use and of the unit being counted - A segmentation by the places commerce happens across Meta's apps, with every assumption labeled and stated in round numbers - Correct conversion from monthly or weekly behavior to a daily count, and removal of people counted in more than one segment - A sanity check against Meta's overall daily audience, plus a range showing which assumption moves the answer most ### Follow-up Questions - If people who only saw a shopping ad were included, how would the answer change, and why might a PM still prefer the narrower definition? - Which assumption would you check first with internal data, and what data would you use? - How would you extend the estimate to the value of purchases that Meta's apps influence each day?