Reading the early signs of product-market fit

The Founders work group compares the first signals they trusted at Pinterest, Coda, Twitch, LinkedIn and Notion.

Updated October 13, 2026

Fit tends to show first as a small group who would hate to lose the product, then as growth you can explain, from users who look like the market you want.

A few people would miss it. Ben Silbermann had about 3,000 Pinterest accounts three months after launch, but a core of users loved it and called him when the site went down. He would watch who keeps coming back over who he expected to adopt it.
Read disappointment next to NPS. Shishir Mehrotra tracks both. Early Coda scored high on disappointment and low on NPS, and Superhuman showed the reverse. He expects a young, differentiated product to show its first real signal in disappointment scores.
Growth settles the market question. Emmett Shear set a 20 to 25% monthly growth bar for Justin.tv's gaming project. It grew 30% a month and kept growing for almost nine months before it became Twitch. He would apply that bar once the product works for its best customer, and calls good press plus "kinda working" the most common false positive.
A churned customer can still be a believer. Uber's team dropped Coda in a day and handed over about 30 fixes. Emmett reads a list like that as a believer when the items point to one underlying job, and as a different product when they scatter.
Fit comes in stages. Reid Hoffman separates initial fit from scale fit, and asks founders for evidence of the move from beachhead to whole market. Ivan Zhao saw no single moment at Notion: people cared, then reached out, then paid, and growth bent after Notion 2.0 in 2018.

Group chat with Emmett, Ben, Ivan, Reid, Shishir — the Founders work group

Question:

What signs tell you a startup has product-market fit?

Ben SilbermannFounder and Chairman of Pinterest. Founder of How We Feel

The earliest sign I trust is a small group of people who love the product enough that they'd be upset if it disappeared. The headline numbers can still be small at that stage. In June 2010, three months after we launched Pinterest, we had about 3,000 registered accounts. That was not impressive, "but the few people who used it, myself among them, actually really loved it." So we built around that small group of fanatical users instead of changing the product.

forbes

One concrete version of "love" was the support load. I kept my cell phone number on all the customer support emails, so when the service went down, people called me personally to say they couldn't get to their pins. Getting a phone call when something breaks tells you the product has become part of someone's routine.

YouTube

The second sign is where the love comes from. Our first real users were people I grew up with in the Midwest and people from the creative industries I met at a conference in Utah. Silicon Valley mostly ignored Pinterest for the first year and a half. If we had waited for fit to show up among tech-forward early adopters, we would have missed it, so I'd look at who actually keeps coming back and not at who you expected to adopt it.

YouTube

Before any of that, you need one thing in the product that is worth someone's time. Our failed iPhone app had lots of features and nothing special, so we got no useful feedback. With Pinterest, the one thing was making collections look good enough that people wanted to show them to friends.

startuparchive

My own test for the first milestone was simple: go somewhere and see a stranger using something I made and finding it useful.

Shishir MehrotraCEO of Superhuman (formerly Grammarly). Co-founder of Coda and former Chief Product Officer of YouTube

The clearest sign at Coda was the product spreading on its own. Our first big customer was Uber, and the moment I knew we were onto something was when people started calling to say, "I know you have me limited to my team. Can I expand this to another team?" Coda was never a product you could force anyone to use. Users either loved it and evangelized it, or they gave up. So when someone on one team carried it into a second team, that told me more than any dashboard.

Apple Podcasts

Ben's test of whether people would be upset if the product disappeared is Rahul Vohra's disappointment question, and I think it should be read next to a second score. I track two:

1️⃣ Disappointment score. This is Rahul Vohra's question: "How disappointed would you be if you could no longer use this?"

2️⃣ Net Promoter Score (NPS), which Fred Reichheld created: "How likely are you to recommend it?"

Coda and Superhuman came out with nearly opposite results. Coda's disappointment scores were very high from the start, because once a team rebuilds its work in Coda, replacing it would take ten other products. Our NPS started low, though, because adopting Coda meant changing how a team works, and people hesitate to recommend that. Superhuman had high NPS and lower disappointment, because Gmail was always there as a fallback. Fred's explanation was that disappointment matters most when a product is very differentiated, and NPS matters more as a market matures and products start to look alike. That means an early startup will usually see its first real signal in disappointment scores.

Apple Podcasts Rahul's public write-up of the method is very good.

coda

The best signal is a customer who still believes in you after you've let them down. Noam's team at Uber stopped using Coda in a single day, and they handed us a list of about 30 things they needed before they would come back. Losing 100% of our users in one day was brutal. But they still believed in the vision and spent real time telling us what was missing, and I read that as a sign we were close to fit.

Emmett ShearCEO of Softmax. Founder of Justin.tv and former CEO of Twitch

Ben's small group of fanatics is where fit starts, but love alone tells you that you have a product. It takes growth to tell you that you have a market. The cleanest market signal I know is sustained growth you can explain mechanically. At Justin.tv we ran two skunkworks projects with three months of runway each. The bar for the gaming one was 20 to 25% monthly growth in usage. Justin.tv gaming grew 30% a month for those three months, and kept growing at 25 to 30% a month for almost nine months before we launched it as Twitch. By the time we registered the new domain, the market question was already settled

Spotify+1.

Socialcam, the other project, is the useful counterexample. It got good press, and everyone agreed it was a neat product that was "kinda working." It never hit its growth goal. Good press plus "kinda working" is the most common false positive I've seen.

Three signs matter more to me than any single number:

1- A closed loop: Our loop was simple. We made the product better for game streamers, recruited more of them, and every streamer who came over brought their whole audience. When their complaints turned straight into the feature list and the next round of recruiting got easier, we knew the loop was real.

2- Excitement out of proportion to the payout: When I asked streamers whether they'd care about monetization that might pay them $3 a month, they said "absolutely." That reaction told me they were starved for the real thing they wanted: money, fame, and love, by which I mean feedback that their creative work was wanted

Spotify.

3- Users recognize it instantly: For the people who loved StarCraft streams, the value was self-evident the moment they saw it. "This is what I've been waiting for." You shouldn't have to explain the product to the people it's for.

If you have to argue yourself into believing you have fit, you don't have it yet.

Reid HoffmanCo-founder of LinkedIn, Inflection AI and Manas AI. Partner at Greylock

Before you build around your fanatics, check whether they look like the market you want to win. Pinterest's early lovers were Midwest friends and creative professionals, people who resembled the eventual mainstream audience. Sometimes the loudest fans are a niche that pulls you away from it. I split it into two stages: initial product-market fit and scale product-market fit. A product can be deeply loved by a small niche and still never become a business.

LinkedIn hit this early. A group calling themselves LIONs, LinkedIn Open Networkers, told us, "your product's for us." My answer was that LinkedIn was for billions of professionals. We made room for the LIONs but didn't build everything around them. If we had treated their enthusiasm as product-market fit, LinkedIn would not be what it is today.

Apple Podcasts

The concrete test is whether the love carries over as you widen the audience.

-> In enterprise software, a narrow first market is the right move. You sell to banks, then other industries, or to HR, then finance. The signal is that each new segment adopts with less custom work than the last.

-> In consumer and network products like Airbnb, starting with a niche doesn't fully work. The signal is pull from people who look nothing like your early adopters. At LinkedIn that came through invitations: members brought in colleagues who would never have found us on their own.

Emmett's Socialcam point matches what I saw at SocialNet, before LinkedIn. It had one of the best matching engines and very positive reviews, but users weren't engaging with each other, and that engagement was what mattered.

The test I use with founders: can you describe the move from the beachhead to winning the whole market, and do you have evidence for it today?

Spotify

Ben SilbermannFounder and Chairman of Pinterest. Founder of How We Feel

I agree with Emmett that growth is what settles the market question, but at Pinterest it came after the love by a long stretch, and the hard part was what to do in between. When growth is flat and a few people love the product, a founder has to decide whether the product is wrong or whether it simply hasn't reached the right people yet. At Pinterest I bet on the second answer. I thought the product was pretty cool, and I considered myself a relatively normal person. The core concept was also very simple: collect things you like, and look at collections other people made. So I judged there was a better chance we hadn't put it in front of the right people than that something was terribly off in the idea.

YouTube

That judgment only works if the small group of users who do find the product behave like the people you built it for, which is close to Reid's test. Ours did. They showed up in Iowa and Utah, they used it the way we did, and they were ordinary people who planned homes and collected ideas. So our work became finding more people like them. If even your best-matched users drift away, that is a product problem, and more distribution won't fix it.

Expectations also change how you read the signal. I didn't have very high expectations, and I think that made a big difference. If you plan on a million users in 12 months, 3,000 accounts looks like failure, and you start changing the product too early. If you're looking for a few people who love it, 3,000 accounts with a fanatical core looks like a start. Emmett's 30% monthly growth is the proof I'd want before calling it fit. A loved product with slow growth is still the case where you should keep going.

YouTube+1

On Shishir's two scores, Pinterest had the "recommend" side built into the product. A collection only felt worth making if it looked good enough to show your friends, so sharing was the main use of the product. Each person who showed off a board was recommending Pinterest without us asking.

startuparchive

Question:

Emmett, you set a bar of 20 to 25% monthly growth and said that if you have to argue yourself into fit, you don't have it. Shishir described Uber's team dropping Coda in a single day, handing over a list of about 30 missing features, and he read that as a sign Coda was close to fit. Would your growth test have killed Coda at that point? If not, how do you tell a believer who churned from the 'kinda working' false positive you saw with Socialcam? Please cite only public sources.

Emmett ShearCEO of Softmax. Founder of Justin.tv and former CEO of Twitch

No, the growth test wouldn't have killed Coda at that point, because it measures something else. We set the 20 to 25% bar to choose between two projects that each already had a working product and three months of runway

Spotify. Uber dropping Coda happened before that stage. Growth tells you whether the market is pulling. Before the product works for its best customer, there's nothing for the market to pull on yet.

To tell Shishir's churned believer apart from Socialcam, look at what kind of feedback you're getting. Socialcam got praise: good press and people saying "this is actually kind of neat." Praise costs the giver nothing and tells you nothing about what to build next. Noam's team handed over a finite list of about 30 things and a condition for coming back. That's a spec, and it's the same thing our streamers gave us. When they said "you don't do this, you don't do that," it went straight onto our feature list, we fixed it, and they switched

Spotify.

The test only counts if you check the list against the real need. When streamers asked for a big red button, I'd ask what their life looked like after I built it. The real answer was always money, fans, or love

Spotify. A churned customer whose 30 items all point to one underlying job is a believer. A churned customer whose 30 items are scattered wants a different product.

The growth test comes back after that. You ship the list, the believer returns, and the next customer like them should adopt with less work. If you've closed the list and usage still doesn't compound, the 30 items were a polite way of saying no.

Question:

Ivan, Ben says a loved product with slow growth is still a reason to keep going, while Emmett wants mechanical growth of 20 to 25% a month before calling it fit. Notion publicly went through a near-death point and rebuilt the product in Kyoto around 2015 before growth arrived. What signal told you the first version was a product problem, and what signal after the rebuild told you Notion had fit? Please cite only public sources.

Ivan ZhaoFounder of Notion

So, I'll start with a confession: for Notion it never felt like a binary moment. Nobody rang a bell. It was a gradual ramp: people cared, then people reached out, then people paid. Even today it feels small next to where it could be.

YouTube

The signals I trust most, in the order they showed up for us:

People build things with your product and show them to others. The first version of Notion, a Webflow-meets-Figma programming tool, ran two or three years and taught us that most people don't want to program their own tools.Apple Podcasts After 2.0, people made their own setups out of the blocks and shared them. Some consultants and template makers quit their day jobs to help other teams set up Notion.Apple Podcasts Once other people can earn a living on top of your product, you have something.
The growth curve bends after a specific change you can name. This is close to Emmett's mechanical growth, though ours took far longer than three months to read. We launched in 2016, but real growth came after 2.0 in 2018. On Ben's question of product wrong versus wrong people: our first version was the product being wrong, and more distribution would not have saved it. 2.0 was the version where the curve answered.Apple Podcasts We passed 1M users in early 2020 and 100M in 2024.
Shishir's team-to-team spread had a cousin at Notion: personal users carrying it into their jobs. Every knowledge worker keeps notes somewhere in their personal life, so the consumer love became the enterprise channel.Apple Podcasts
Investors go out of their way to find you. One firm tracked down our office, which had no public address, and sent dog treats because we had a new office dog. That was when I paused and thought, why do people want this so much?Apple Podcasts

I have no formula for engineering PMF, and luck played a part. Like Ben with his phone number, I answered every support ticket myself for the first couple of years and treated each one as product feedback. The other half is having your own stance on which feedback to ignore. Emmett's scattered-list test matters even more for a flexible tool like Notion, because every ticket asks it to become a different product.

Apple Podcasts

Ask a follow-up

Founders

467

Founders

4M+ insights

Founders from Pinterest, LinkedIn, Notion & 2 more

by SuperMe

Frequently Asked Questions

How is early traction different from product-market fit?
Traction responds to a launch, press or founder effort and fades when that stops. Fit keeps compounding through the product's own loop, and the love repeats with strangers who match the first fans.
What should you do when product-market fit isn't coming?
Make the next attempt a bounded test with a target and a deadline the cash can cover, check that the test was fair, and change course on a miss. With no promising group or runway left, return the capital.
How do you pressure-test a startup idea?
Set a behavior bar before the team gets attached, put an early version into someone's real work, and write down the ways the company could fail even if early users love it.
When should a founder drop an idea?
When people who have the problem can find the product, try the full version and still don't come back. Low signups and investor doubt alone are weak reasons to quit.
How do founders find a problem worth solving?
Start from a problem you will care about for years, find people whose behavior shows they have it too, and know why you can make progress where others see risk.
What should a first-time founder do first?
Start, choose a cofounder with care and get something in front of strangers early. The group splits on whether research or a rough product comes first.
How do you size a market before building?
Start from a behavior people already have, ask what has kept anyone from winning the market, and let growth or repeat use tell you its size.
How does a startup stand out in a crowded market?
Pick one experience people return to, start with the people whose choice brings everyone else, and check whether users come back for a second job.
Where can an AI startup win against the model companies?
Around what takes sustained work to copy: a group's accumulated taste, a team's workflow, trust between people or a creator's audience.
How do you validate an idea with customers?
Go out to learn, ship one thing worth a stranger's time, watch who comes back on their own and then ask them why.
How do you choose a consumer products category?
Look for a need people already recognize, evidence that they act on it, and unit economics that work across the whole purchase cycle.

All starting a startup questions →

Frequently Asked Questions

Reading the early signs of product-market fit

Founders

Frequently Asked Questions

How is early traction different from product-market fit?

What should you do when product-market fit isn't coming?

How do you pressure-test a startup idea?

When should a founder drop an idea?

How do founders find a problem worth solving?

What should a first-time founder do first?

How do you size a market before building?

How does a startup stand out in a crowded market?

Where can an AI startup win against the model companies?

How do you validate an idea with customers?

How do you choose a consumer products category?

Your ideas, super powered.

Reading the early signs of product-market fit

Founders

Frequently Asked Questions

How is early traction different from product-market fit?

What should you do when product-market fit isn't coming?

How do you pressure-test a startup idea?

When should a founder drop an idea?

How do founders find a problem worth solving?

What should a first-time founder do first?

How do you size a market before building?

How does a startup stand out in a crowded market?

Where can an AI startup win against the model companies?

How do you validate an idea with customers?

How do you choose a consumer products category?

Your ideas, super powered.