Product-market fit feels like a fog — until you turn it into one number you can improve. One four-question survey does exactly that.
This is the method Rahul Vohra used to steer Superhuman from a vague hope to a measured product-market-fit score that climbed quarter over quarter — built on a benchmark Sean Ellis established across roughly a hundred startups. Here's the survey, the number to aim for, and how to act on the answers. It pairs with the full build method in how to build an MVP.
First principle
What product-market fit actually is
Product-market fit isn't press, funding, or a nice-looking demo. It's a measurable emotional dependency: enough of the right people would genuinely miss your product if it vanished. Everything else — growth, retention, word of mouth — follows from that. So the goal is to measure the dependency directly, early, even with a small number of users.
The benchmark
The 40% test
Ask active users: “How would you feel if you could no longer use this product?” If 40% or more say “very disappointed,” you have the leading indicator of product-market fit.
Sean Ellis found that companies below ~40% tend to struggle for growth, while those above it consistently found traction. It works because it measures how much people would miss you — a precursor to sustainable growth — rather than a vanity metric you can fool yourself with. Below 40% isn't failure; it's a direction: raise the number.
Free template
The survey — copy this
Four questions. Put them in a simple form (Typeform, Google Forms, or a page in your own app) and send to recent, active users. Replace [product] with your product's name.
- Q1
How would you feel if you could no longer use [product]?
Very disappointed / Somewhat disappointed / Not disappointed
The one that measures PMF.
- Q2
What type of people do you think would most benefit from [product]?
Open text
Reveals who your fans are, in their words.
- Q3
What is the main benefit you receive from [product]?
Open text
Your true value proposition, in their words.
- Q4
How can we improve [product] for you?
Open text
Surfaces the blockers worth fixing.
Method
How to run it
- Ask active users only. People who've used your core product at least twice in the last couple of weeks — not sign-ups who never engaged.
- ~40 responses gives you a direction; 100–200 gives you real insight. Don't wait for perfection.
- Never re-survey the same person. Survey fresh cohorts each time so your benchmark stays honest.
- Tag each respondent with a persona (role, company type) so you can segment the results.
The engine
How to act on the answers
The score is the start, not the finish. Here's the engine that turns responses into a roadmap.
- Segment to find your believers. Filter to the “very disappointed” users and see which persona clusters there. That's your true market — often narrower and more specific than you assumed. Narrowing focus to them alone can lift your score immediately.
- Convert the on-the-fence group. Among “somewhat disappointed” users, look only at those who value your main benefit (ignore the rest — no feature will win them). Their answer to “how can we improve?” is your highest-value to-do list.
- Ignore the “not disappointed.” Building for people who don't care about your core value dilutes the product and corrupts the roadmap.
- Build a 50/50 roadmap. Half your effort deepening what your believers love (defend your edge); half removing the top blocker for the almost-fans. Prioritise low-cost, high-impact work first.
- Make the score your north star. Re-run the survey each quarter with new users and track the number over time. As you grow past early adopters it may dip — keep improving faster than it dilutes.
