How to Know If You Have Product-Market Fit

Sean Ellis defined product-market fit as 40% of your users saying they'd be "very disappointed" if they couldn't use your product. Most founders don't measure it - they feel for it. The problem with feeling for it is that confidence and fit are easy to confuse when you're close to the product.

Why this happens

The median time to product-market fit for successful B2B SaaS is 18-24 months from first paying customer. That's not a long time in absolute terms, but it's a long time to make decisions without a clear signal that you're moving in the right direction. Most founders experience a period where some customers love the product, some churn quickly, and the signal is noisy enough that it's hard to tell whether you're close to fit or far from it.

The root cause of misreading fit is aggregating data across segments that don't belong together. A 30% "very disappointed" score looks like you're close to the 40% threshold - but if that 30% is concentrated entirely in one segment and the other segments are at 10%, you've already found fit in one market and are diluting the signal by selling to others simultaneously.

What to check first

Four questions that give you a sharper picture than a single survey score:

Would customers pay more if you raised prices? Customers with strong product-market fit don't push back hard on price increases - they accept them because the alternative (switching or going without) costs more than the increase. If a 20% price increase would cause significant churn, buyers are satisfied but not dependent.
Do customers refer others unprompted? Word-of-mouth that you didn't manufacture is the clearest behavioral signal of fit. Track whether new customers are coming from customer referrals, and whether those referrals are converting at a higher rate than other channels. Referred customers who convert well signal that your retained customers believe in the product enough to put their reputation behind it.
Are you retaining 90%+ over 12 months? Annual retention above 90% means your product is delivering enough ongoing value that customers see no reason to leave. Below 90%, you're losing more than 1 in 10 customers per year - compound that over 3 years and you've replaced your entire customer base twice.
Is your growth pulling or pushing? Pulling growth: customers upgrade without prompting, your sales cycle is shortening as word spreads, inbound leads arrive with context about your product. Pushing growth: every new customer requires active selling, growth stops when your team stops pushing, and you can explain every deal as a one-time effort. Pulling growth is a fit signal. Pushing growth means demand isn't self-sustaining yet.

How to fix it

Run the Sean Ellis survey with your active users - users who have been active in the last two weeks and have used the product at least twice. Segment the results by company size, industry, and role. Don't aggregate.

If your "very disappointed" score is above 40% in one segment and below 20% in others, you have fit in that segment. Stop trying to expand until you understand what makes that segment different and can use it to find more buyers like them.

If your score is below 40% across all segments, find the 10 customers who are closest to "very disappointed" - the ones who scored the product 8-9 out of 10 on a satisfaction scale. Interview each one. Ask them: what specific job were you using the product for? What outcome did you get? What would you lose if the product disappeared tomorrow? Their answers will tell you which version of your product is closest to fit, which customers that version serves, and what you'd need to build or change to get there.

One constraint that matters: don't run this exercise across your entire customer base if your best customers are hidden inside a larger group of buyers who were never a good fit. Deliberately churning the wrong segment - by raising prices, narrowing your ICP, or changing your marketing - often reveals a stronger fit signal among the customers who stay.

Remove the guesswork

Finding product-market fit faster requires knowing which customers are closest to fit right now. RightAudience maps the characteristics your retained, high-satisfaction customers share so you can find more buyers who match that profile - and stop spending acquisition budget on segments where fit is unlikely.

Find your highest-fit customer segment