The north star metric

A product team without a shared metric argues about features. A team with a bad metric ships growth that looks good on a slide and quietly destroys the business. The north star metric is one number that best captures the value your product delivers to customers, that tends to lead revenue and that teams can actually move.

The big idea

Amplitude's North Star Framework (popularized after Sean Ellis's growth work) asks three things of the metric:

1. Reflects customer value. It moves when users get the core job done, not when they merely open the app.
2. Leads business results. Over months, growing it should grow revenue, retention or marketplace liquidity — not just pageviews.
3. Is actionable. Teams can see which product changes move it within weeks, not only after a quarterly finance close.

Prefer counts of valuable outcomes over pure ratios when you need a shared company scoreboard. "Nights booked" can grow forever as the marketplace grows; "conversion rate" can look healthy while absolute bookings shrink. Ratios still matter as inputs and diagnostics.

Write the north star as: count of [actors] who [did valuable action] in [window]. Example: "Weekly Learning Users = active users who shared a learning consumed by ≥2 others in the last 7 days" (Amplitude's own framing). Ambiguity in that sentence becomes months of dashboard arguments later.

Treat public examples as patterns, not gospel. Your north star should map to your strategy — if strategy shifts from acquisition to retention, the metric often should too. Airbnb's nights booked works because both sides win when it rises. Slack's message volume works because empty workspaces churn; paid seats without messages are zombie ARR.

Walking through it

For SaaS financial metrics (ARR, churn, NRR) see SaaS metrics. Those are business scoreboards. The north star is usually one step upstream: the customer behavior that causes healthy SaaS numbers. If NRR is the board metric, pick something expansion and retention both feed — seats invited and active, workflows run — not raw MAU.

Good reasons to change the star: strategy shift, business model change or discovering the old metric was gameable. Bad reasons: the chart looks ugly; a new VP wants new vocabulary. When two candidates tie, prefer the one a junior engineer can explain in one sentence. Composite indices ("engagement score = 0.3×A + 0.5×B") die in practice.

Common mistakes

• Copied north stars. "Airbnb uses nights booked" even though you are a B2B workflow tool. Copy the criteria (value, leading, actionable), not the noun.
• Ratios as the only scoreboard. A healthy rate with a shrinking denominator is not growth.
• Changing the star because the chart is inconvenient. Change it when strategy changes.

Check yourself

1. Why is "conversion rate" a weak sole north star for a marketplace?

The rate can look healthy while absolute bookings shrink. Counts of valuable outcomes (nights booked) can grow with the market.

2. Write a north star sentence for a notes product whose value is collaboration.

Count of actors who did a valuable action in a window: e.g. documents collaboratively edited per week.

Key takeaways

• A north star quantifies customer value, leads business results and is actionable.
• Write it as a count of actors doing a valuable action in a window.
• Align it with the business scoreboard; it is usually one step upstream of ARR or NRR.

Further learning

Amplitude's playbook is the clearest practical treatment of north star + inputs.

The North Star Playbook (Amplitude)Put the North Star Framework to work for your product. Get expert tips on defining and integrating your North Star Metric into your development processes.Amplitude

Next: decompose it in metric trees.