Product-market fit, answered
The questions founders ask most about measuring product-market fit — and how PMFtracker works. New to the topic? Start with the glossary or measure your score with the free calculator.
Measure your PMF score → 14-day free trial · No credit card · Pay once, no subscriptionAbout product-market fit
What is product-market fit?
The degree to which a product satisfies strong market demand. Marc Andreessen described it as "being in a good market with a product that can satisfy that market." It's measurable — most reliably via the Sean Ellis survey — not just a feeling. See the full definition.
What is the Sean Ellis test (the 40% rule)?
You ask users "How would you feel if you could no longer use [product]?" and measure the percentage who answer "very disappointed." The benchmark is 40%: at or above it, products have historically been able to grow sustainably. Read the full method.
What is a good PMF score?
40% or higher "very disappointed" signals product-market fit. 30–39% is close — targeted improvements can push you over. Under 30% means keep iterating. More on interpreting your score.
How many responses do I need for a PMF survey?
At least 40 valid responses from engaged users for a directional read, and 100+ for a score reliable enough to show investors. Quality beats quantity — survey engaged users, not every signup. See the sample-size math.
How is PMF different from NPS?
NPS measures how likely existing users are to recommend a product; the PMF survey measures how essential it is. They answer different questions, and PMF is the better leading indicator of fit. NPS vs PMF, in detail.
How do I know if I have product-market fit?
The clearest signals: a Sean Ellis score ≥ 40%, a retention curve that flattens rather than decaying to zero, and strong organic word of mouth. The survey is the one you can measure this week. The six signals.
How often should I measure PMF?
On a cadence — monthly or quarterly — so you build a trend line. A one-time survey is a snapshot; the trend is what reveals whether fit is improving and what investors trust.
About PMFtracker
What does PMFtracker do?
It runs the Sean Ellis survey on your engaged users, calculates your PMF score on the 40% rule, tracks it as a trend over time, segments respondents into your ICP, and exports an investor-ready report.
How does PMFtracker measure PMF?
You embed a survey widget in your product. It runs the Sean Ellis question on engaged users, scores it on the 40% rule, tracks the trend, segments users into your ICP, and runs AI sentiment analysis on the open-ended answers.
Do I need to be technical?
No — PMFtracker is built for non-technical founders. You embed a widget, and the scoring, segmentation, and reporting are automated.
Can I import data from another survey tool?
Yes. If you already collected feedback in Typeform, SurveyMonkey, a spreadsheet, or another tool, import it and PMFtracker will score and analyze it — both the in-product widget and CSV import count as collecting responses.
How much does PMFtracker cost?
A one-time, lifetime purchase — no subscription. List price: PMF Starter $99 and PMF Startup Kit $199, with a launch promo of $79 / $149 for the first 100 customers. New users get a 14-day free trial, no credit card required.
Is there a free trial?
Yes — every new user gets a 14-day free trial with no credit card required, and there's a free PMF score calculator you can use without an account.
Is PMFtracker free for investors?
Yes. Investors and accelerators get complimentary read-only access to the reports founders choose to share — score, trend, and AI insights, never raw responses. More for VCs.
Still have a question? Just measure your score
Run the Sean Ellis survey on your engaged users, see your score against the 40% rule, and track it over time. No credit card, and you pay once — measure forever.
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