North Star Metric: the metric that guides the product

The North Star Metric is the one metric that best reflects the value customers get from a product. How to choose it, its input metrics and its limits.

info Quick Definition

The North Star Metric is the single metric that best captures the value customers get from a product. It guides the whole team’s decisions, because any piece of work should be explainable in terms of how it moves that metric. It is supported by a set of input metrics that teams can actually move day to day.

What is it and why does it matter?

A product generates many metrics: active users, time on screen, conversions, revenue, retention. Each area of the team optimizes its own, and it is easy for priorities to contradict each other. The North Star Metric resolves that conflict by giving a single reference point: if this goes up, the product is giving someone more value.

Amplitude defines it as the single metric that best captures the value customers get from the product. Its criteria are three: it reflects what customers value, it sits within the sphere of influence of product and marketing, and it leads revenue growth.

How do you choose a good one?

Amplitude proposes three criteria that work as a checklist:

Focused on customer value. The question is what the person gets when they use the product, not what the company does.
Within the sphere of influence. Product and marketing must be able to move it through their work.
A leading indicator of revenue. It should anticipate revenue growth, not just record it after it has happened.

Amplitude gives illustrative examples, not official statements from companies. One is a self-serve SaaS: trial accounts with more than three active users in week one, which is more precise than counting trial accounts in total. Another is a grocery delivery service: total items received on time each month. It also mentions Airbnb and its nights-booked metric as a widely cited case: it signals that travelers found a place worth staying.

On the other side, Amplitude lists as poor North Stars vanity metrics and lagging indicators: daily active users (DAU), registered users, page views, time on page, ad impressions, downloads, story points, and MRR or ARR. Its nuance is that none is bad in itself, only as a North Star.

Startups.com summarizes it with a line worth keeping: a good North Star Metric is an input the team can move this week, and that also predicts the business outcome statistically. That definition differs from Amplitude’s, and this is the tension of the topic, detailed below.

What are input metrics?

Input metrics break the North Star into levers. Startups.com describes the common practice of one North Star plus three to five input metrics that decompose it, attributing it to Reforge. Amplitude raises the same idea: three to five influential, complementary factors that teams can move through their daily work.

The key is that each input metric has an owner. Illustrative example: if the North Star is “items delivered on time”, the inputs might be inventory accuracy, order preparation time and driver availability. Each team knows what to move and can see whether it is succeeding.

Here the tension appears. Amplitude’s article quotes John Cutler, a former Product Evangelist at the company: if you can move your North Star directly, it is probably not a good North Star. Its webinar on the topic adds that a good North Star is not immediately actionable, which is why input metrics are needed. Startups.com proposes the opposite: that it should be something the team can move this week. The practical reading is that the North Star should sit one level above what the team controls directly, and the input metrics are the ones that move day to day.

How does it connect to design?

For a designer, the North Star is a way to justify work with more than the opinion of the customer. A redesign of onboarding should be connectable to an input metric, such as activation in the first week, which in turn pushes the North Star. That link is a hypothesis the team must check with data, not something to take for granted.

It also helps choose between ideas. If a proposal improves satisfaction but has no relation to the metric, the team has a clear question to answer before building it. The prioritization frameworks can order those decisions.

If you do not yet know what to measure, read outcomes versus outputs first. And for the experience side, the design team’s KPIs should point in the same direction.

Example

Illustrative example: a language-learning app defines as its North Star “lessons completed by users who study at least three days a week”. There are three input metrics: users who complete their first lesson on day one, study days per week in month two, and streak retention after a pause. The design team works on streak retention: it redesigns the recovery notification sent after two days without studying. The test shows the input metric rising, and the team checks whether the North Star follows the same path the next quarter.

For your product: write the metric you think summarizes the value, and ask whether someone on the team could move that metric this week. If the answer is no, look for the input metric that can be moved.

When should you NOT use it?

When the product is very new and does not yet know what value it delivers. It is better to test hypotheses than to fix a metric.
When the metric becomes a goal in itself and starts distorting the product. If the team optimizes clicks without the experience improving, the metric no longer serves.
When there are several business units with different values. Forcing a single North Star can hide real conflicts.
When the metric is a vanity indicator. DAU, registered users or page views move easily and say little about the value received.

Common mistakes

Having several North Stars. Alignment is lost.
Choosing DAU or registrations because they are easy to measure; Amplitude lists them among vanity metrics.
Setting it and never reviewing it. Amplitude says it has changed its own at least three times.
Not defining input metrics, which leaves the North Star as a number with no owner.
Presenting it as a magic formula. Amplitude warns there is no one-size-fits-all approach.
Using the North Star to evaluate people instead of product decisions.

Sources

Frequently asked questions

What is the North Star Metric?

It is the single metric that best captures the value customers get from a product. According to Amplitude, it should reflect customer value, sit within the team’s sphere of influence and be a leading indicator of revenue.

How many North Star Metrics should a product have?

One. Several North Star Metrics dilute the alignment that justifies having one. Each should be supported by three to five input metrics that teams can move.

What is the difference between a North Star Metric and a KPI?

A KPI can measure any part of the business. The North Star Metric is one metric, the one that summarizes the product’s value. Each team’s KPIs should help move it.

Can the North Star Metric be DAU or registered users?

Amplitude lists them among poor choices, along with page views, downloads and MRR or ARR. It clarifies that no metric is bad in itself, only as a North Star: they measure activity or revenue, which do not always reflect the value the customer receives.