Product Manager Interview (+ AI PM) · Metrics & Analytics · Lesson 1 of 3
North-star metric & defining success
A north-star metric (NSM) is the single measure that best captures the core value your product delivers to users — and that, when it grows, the business grows with it. Good NSMs track delivered value (e.g. nights booked, messages sent, weekly active teams), not vanity counts like total signups.
- Value-aligned: it goes up only when users get real value (Airbnb → nights booked, not downloads).
- Leading, not lagging: a good NSM predicts future revenue rather than just reporting the past.
- Actionable: teams can influence it through the product.
- Break it into input metrics you can move (e.g. NSM = active users × actions/user).
Vanity metricsTotal registered users, page views, and app downloads look good on a slide but can climb while the product dies. Pick a metric that falls when users stop getting value.
Tie the metric to the goalWhen asked 'what metric would you track', first restate the product goal, then derive the metric from it. A metric with no stated goal behind it reads as guessing.
◆ Lock it in
- The north-star metric captures delivered user value and predicts business growth.
- Prefer value-based, leading, actionable metrics over vanity counts.
- Decompose the NSM into input metrics teams can actually move.
Feynman drill — say it out loudExplain why 'nights booked' is a better north-star for Airbnb than 'total app downloads'.
Step 1 rate your confidence · Step 2 pick your answer
Which is the best north-star metric for a messaging app?
Step 1 — how sure are you?