Define KPIs for Trust, Virality and Selection at a Used-Bicycle Marketplace

You are the product manager of an online marketplace where people buy and sell used bicycles. The CEO has set three goals for the business: strong trust between the buyers and sellers on the platform, a marketplace that spreads virally, and the best possible selection of bicycles on offer. Define the key performance indicators (KPIs) you would use to track progress on each goal. ### Clarifying Questions - Is the sale completed on the platform (payment and confirmation in the app), or do buyers and sellers connect here and finish the deal offline? This decides which trust and sale events can be observed. - Are the sellers only private individuals, or also bike shops and dealers? - Is the marketplace still building up buyers and listings in its first cities, or is it established? ### Part 1 — Trust between buyers and sellers Propose KPIs that show whether buyers and sellers trust each other and the platform. ```hint Trust shows up in behavior Look beyond what people say in ratings: find the actions people take only when they feel safe, and the problems that appear when trust breaks. ``` #### What This Part Should Cover - A primary trust KPI with leading and lagging supporting metrics. - Signals from both sides of the marketplace. - Negative indicators such as fraud, disputes and items that differ from their listing. ### Part 2 — A viral marketplace Propose KPIs that show whether the marketplace grows through its own users rather than through paid acquisition. ```hint Measure the loop Virality is a loop: an existing user exposes the marketplace to someone new, who joins and then exposes others. Measure each step of that loop and how fast it turns. ``` #### What This Part Should Cover - A definition of the viral loop, measured on both the buyer and the seller side. - The quality of the users the loop brings in, not only their number. - Separating organic growth from paid or seasonal growth. ### Part 3 — The best selection of bicycles Define what the best selection of bicycles means for this marketplace, and propose KPIs for it. ```hint Best for whom? A large catalog is not automatically a good one. Compare what buyers look for with what is listed, and consider how good each listing is. ``` #### What This Part Should Cover - A buyer-centered definition of a "best" selection. - Metrics for how well supply matches demand, and for listing quality and freshness. - How the selection connects to sales outcomes. ### What a Strong Answer Covers - KPIs defined precisely enough to compute (numerator, denominator, time window), not vague concepts. - The tensions between goals, such as fast viral growth against trust, or more listings against listing quality, with guardrails. - One overall outcome that ties the three goals together. - How measurement changes if sales happen off the platform. ### Follow-up Questions - Your viral KPI is rising quickly, and so are scam reports per thousand conversations. What do you do? - If you could track only one KPI for the whole business, which would it be and why? - How would you measure trust if sales are completed offline and you never see the payment?