Outcome

Get product-market fit signal.

Product-market fit is not a vibe. It is three measurable signals: retention curve, expansion revenue, and unprompted user growth. The diagnostic checks each against your current numbers and labels how close you are.

Verified May 22, 2026 · editorial policy

TL;DR

Outcome: Product-Market Fit Signal
Summary: Product-market fit is not a vibe. It is three measurable signals: retention curve, expansion revenue, and unprompted user growth. The diagnostic checks each against your current numbers and labels how close you are.
Why hard for most: PMF is a portfolio of three signals, not a single signal. Founders measure one (usually growth) and ignore the other two (retention and expansion). With one of three signals visible, the answer to 'do I have PMF' is always 'maybe' – which means 'no', because PMF reads as 'obviously yes' when it lands.
The move: Measure all three signals against published thresholds. Retention curve flat at week 6 or higher. Expansion revenue greater than 30 percent of new revenue. Unprompted user growth at 5 percent week-over-week or higher. Two of three: you are close. Three of three: you have PMF.
What to track: Week-6 cohort retention as the canonical leading signal. Easier to measure than the other two and the strongest predictor of long-term PMF. Below 20 percent: the product does not yet match the market. Above 30 percent: you are in the zone.
Last verified: May 22, 2026

What the stuck-state looks like

You read 'you will know when you have PMF' a hundred times. You have shipped, you have customers, you have churn, and you have no idea whether you are close. The waiting-to-feel-it framing is the worst possible navigation aid for the most important question pre-revenue founders face.

Why this outcome is hard for most founders

PMF is a portfolio of three signals, not a single signal. Founders measure one (usually growth) and ignore the other two (retention and expansion). With one of three signals visible, the answer to 'do I have PMF' is always 'maybe' – which means 'no', because PMF reads as 'obviously yes' when it lands.

The Brunson move

Measure all three signals against published thresholds. Retention curve flat at week 6 or higher. Expansion revenue greater than 30 percent of new revenue. Unprompted user growth at 5 percent week-over-week or higher. Two of three: you are close. Three of three: you have PMF.

The 4-step walk

01
Plot the retention curve
Cohort users by signup week, plot percent active week 1 through week 12. Healthy curve flattens at 30 percent or higher by week 6. Curves that continue to drop have a retention problem masquerading as a growth problem.
02
Measure expansion revenue as a percent of new revenue
Of this month's revenue, what percentage came from existing customers upgrading vs new customers signing up. Healthy expansion at 30 percent or more signals that the offer ladders without acquisition spend.
03
Track unprompted growth (referrals + organic mentions)
Of this week's signups, how many came from a referral, an unprompted social mention, or an organic search. Above 5 percent week-over-week growth from these sources signals real market pull.
04
Score the portfolio: 0, 1, 2, or 3 signals green
Zero green: PMF is far. One green: pre-PMF, ship-and-measure cycle. Two green: close, optimise the red signal. Three green: scale, do not change the offer.

The mistake most founders make chasing this

Reading the growth signal alone and concluding PMF based on a launch spike. Launch spikes are not PMF; they are launch spikes. The retention curve at week 6 is the honest answer. Most launch-spike products have retention curves that drop to single digits by week 6 – that is the diagnostic, not the spike.

What to track so you know it is working

Week-6 cohort retention as the canonical leading signal. Easier to measure than the other two and the strongest predictor of long-term PMF. Below 20 percent: the product does not yet match the market. Above 30 percent: you are in the zone.

Questions founders ask

How many customers do I need before the retention curve is meaningful?

30 cohort users for directional signal, 100 for confident signal. Below 30 the noise dominates. Above 100 the cohort behaviour is repeatable and the curve is honest.

Can I have PMF without expansion revenue?

Possible if the product is genuinely one-time-purchase shaped (a course, a tool, a download). For SaaS, expansion revenue absence at 30 percent or more usually signals the value ladder is missing rungs, even if acquisition is healthy.

What if I have all three signals at low volume?

Then you have early PMF and need to scale acquisition without changing the offer. The most common failure pattern at this stage is changing the offer in pursuit of scale; the offer is the thing that produced the signal.

Run the diagnostic against your live page

The free 90-second Launch Diagnostic runs the Hook / Story / Offer triage on your actual URL and labels which of three blocks is between you and product-market fit signal. Same triage that powers this page, applied to your specific situation.

Get the free diagnostic Other outcomes