Product/market fit means your product meets a real need in a good market so well that your ideal customers sign up, stay and tell others. Marc Andreessen defined it as being in a good market with a product that can satisfy that market. The most common test is the Sean Ellis survey: if at least 40% of users would be very disappointed to lose your product, you likely have fit.
Key takeaways
- Product/market fit = a good market + a product that satisfies it.
- The Sean Ellis test: 40% or more 'very disappointed' is the usual benchmark.
- Retention, word of mouth and customers asking to pay are the behavioral signs.
- Fit isn't permanent. A market shift or a new technology can take it away.
"That will never work."
Netflix co-founder Marc Randolph heard that over and over when he pitched mail-order DVD rentals. Even his wife had almost no confidence in the idea. And for the first few versions, the doubters were right.
Then Netflix dropped due dates and late fees, and offered a monthly subscription for unlimited rentals. Engagement shot up. Churn dropped like a stone. As Randolph put it, "If there was a moment when Netflix stopped being a start-up and became a real company, it was then."
That moment is product/market fit.
What does product/market fit mean?
In Chapter Ten of The Subscription Playbook, I put it simply: having good product/market fit means you've created an offer people want. "Your offer fits the market so well that your ideal customers sign up because they're getting all the value they could need from you."
Marc Andreessen's 2007 definition is the one most people quote: "Product/market fit means being in a good market with a product that can satisfy that market."
Notice there are two halves. A great product in a tiny or unwilling market doesn't have fit. Neither does a mediocre product in a huge one.
How do you measure product/market fit?
The most widely used measure is the Sean Ellis test. Ask active users one question: "How would you feel if you could no longer use this product?"
PMF score = "Very disappointed" responses ÷ Total responses × 100
A score of 40% or more suggests you have fit.
How Superhuman went from 22% to 58%
Before launching, Rahul Vohra surveyed Superhuman's early users. Only 22% said they'd be very disappointed. Instead of launching anyway, he segmented the answers, focused on the users who loved it, and fixed what held the others back. About three quarters later, the score had reached 58%.
Run your own with the Product/Market Fit Survey Scorer, using the ready-made Sean Ellis survey template.
Product/Market Fit Survey ScorerRun the Sean Ellis test and score it.Open the free tool →The signs you have it (and the signs you don't)
| You probably have fit when... | You probably don't when... |
|---|---|
| Customers stay month after month | Churn is high and nobody can say why |
| New customers arrive by word of mouth | Every sale needs a big push |
| Customers ask to pay, or accept a price rise | Discounts are the only thing that closes deals |
| Usage grows without you nagging | Sign-ups log in once and disappear |
Andreessen described the second column well: "You can always feel when product/market fit is not happening."
What people get wrong
Fit vs a minimum viable product. An MVP is a tool for finding fit. Having one doesn't mean you have it.
Fit vs revenue. You can buy revenue with heavy discounts or advertising. Fit shows up in retention, not just sales.
Fit is forever. It isn't. Chegg had strong fit until free AI tools did much of what students paid for. Read how Chegg lost half its revenue when AI gave away its product.
Score your product/market fit
Run the Sean Ellis test and get your score with the free Product/Market Fit Survey Scorer.
Why it matters for subscriptions
A subscription has to be re-earned every month. Without fit, you'll pour money into acquisition and watch it leak out through churn. With it, everything else in the book (land and expand, network effects, the MOATS framework) starts to work.
What to do next
Survey your active users this week. If you score under 40%, focus on the users who said "very disappointed" and find out what they love.
For four company stories and the full Superhuman method, read the guide to product/market fit, then the step-by-step Sean Ellis test and how Superhuman built its PMF engine.
Back to the subscription and pricing glossary.
Frequently asked questions
Who coined the term product/market fit?
The idea is usually credited to Andy Rachleff of Benchmark Capital, and it was popularized by Marc Andreessen in his 2007 blog post 'The only thing that matters.' Andreessen's definition is still the one most people quote: 'Product/market fit means being in a good market with a product that can satisfy that market.'
How many responses do I need for the Sean Ellis test?
Superhuman's Rahul Vohra said results start to become directionally useful at around 40 responses. Survey people who have used the product recently and enough to judge it, not people who signed up and never came back. Their answers measure your onboarding, not your fit.
Can a service business have product/market fit?
Yes. For a clinic, agency or accounting firm, fit shows up as clients who renew without being chased, referrals you didn't ask for, a waiting list, and the ability to raise prices without losing many clients. You can run the same 'how would you feel if you could no longer use us?' question with your clients.
What comes before product/market fit?
Usually problem/solution fit: evidence that a specific group has a painful problem and that your idea solves it, often tested with interviews, a landing page or a minimum viable product. Product/market fit comes later, when real customers use and pay for the product and keep doing so.
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Robert Coorey, MBA
Robert is the author of The Subscription Playbook and Feed a Starving Crowd and a Director at BPAG Accountants in Sydney. More about Robert.
Sources
- Marc Andreessen, The only thing that matters (pmarchive, 2007)
- Andreessen Horowitz, 12 things about product-market fit
- First Round Review, How Superhuman built an engine to find product/market fit
Facts and prices checked 27 October 2026. Spotted something out of date? Tell us.