[Business/Service] What Is PMF, the Success Equation for Startups?

PMF is one of the terms you hear most often at startups, and one of the most loosely used. People say "we haven't hit PMF yet" all the time, but what they look at to reach that judgment varies from person to person.

PMF (Product-Market Fit) means being in a good market with a product that can satisfy that market. The phrasing Marc Andreessen used in his 2007 essay "The only thing that matters" is still the most widely cited.

What matters here is the order. It is not that the market follows once you build a good product; it is closer to choosing a good market first and fitting the product to it.

Why PMF matters

Before and after PMF, the nature of the money and time a company has to spend changes completely.

• It keeps you from scaling too early on vanity metrics. Downloads and sign-ups can be bought with ad spend. Repeat use and repeat purchases cannot. If you burn marketing budget before PMF, costs grow while the problem remains unconfirmed.
• It becomes the standard for hiring and growing the organization. If you add people before PMF, the whole organization is shaken every time the direction changes.
• It becomes the language of fundraising. You need to be able to explain "who comes back, and why" rather than "how many people used it."

The process of reaching PMF

There is no single right answer, but skipping steps usually makes things more expensive. The flow that repeats in practice looks like this.

• 1. Narrow the customer — "People in their 20s~30s" is not a target. You need to narrow it down to the situation the person is in.
• 2. Validate the problem — Before bringing up your product, first ask how they are solving that problem today. If they are already spending money or time on it, it is a real problem.
• 3. Build it in the smallest possible form — A landing page, a no-code tool, or manual operations are all products too. It is not too late to write code last.
• 4. Confirm through behavior — Look at actual clicks, payments, and return visits, not answers like "I'd probably use it."
• 5. Change only one thing — If you change several things at once, you cannot tell what made the difference.

The key element in reaching PMF

If I had to keep only the single most important thing, it would be this.

Continuously validating with data "what value you will deliver to which customer."

If that sentence sounds abstract, just check two things. First, can you describe your customer in one sentence? Second, can you say what inconvenience that customer goes back to if they stop using you? If you get stuck on both, you are still at the hypothesis stage, not yet a product.

Common indicators of PMF

No single metric can prove PMF. But there are some that become signals when you look at them together.

• Does the retention curve flatten? — If a certain share of users stays over time, there is a real market inside that group. If it keeps converging toward 0, you are not there yet.
• Do repeat purchases and return visits happen voluntarily? — The test is whether people still come back when notifications and coupons are turned off.
• Do users explain it for you? — Referrals and sharing mean users have put the value into words on their own.
• Do people say "it would be a problem if this service went away"? — This is the signal that shows up fastest in qualitative interviews.

What I went through

I learned PMF through failure before I learned it from documents.

When I was building a platform to make angel investing accessible to the general public, I launched an investment amount calculator based on income tax deductions as the MVP and gathered 1,000 pre-launch users. The need was clearly there. But the investment market had contracted sharply at the time. The problem was right and there was a response, but that is when I learned that PMF does not hold if the market timing is wrong. In the end, we changed direction.

When I built an eco-friendly platform, I went in the opposite order. Instead of writing code first, I validated with no-code tools, secured free users, and only then built the app. That is when I confirmed that validation is possible without spending on ads.

In the CrossFit domain, I interviewed 20 gym owners in person and then built an MVP used at 10 locations. Users came. But because we did not design the revenue model alongside it, it did not last long. If there is value, users will gather, but without a designed revenue model it is hard to sustain — that is the note I left myself at the time.

All three times had one thing in common. It was not that the product fell short, but that I moved on to the next stage before sufficiently narrowing down which customer's problem, and which problem, I was solving.

If you do just one thing today

Think of one customer for what you are building right now, and try filling in the following three sentences.

• This person currently solves this problem with ___.
• Using us reduces ___ among those.
• Whether it actually went down is checked with this number: ___.

The point where these three sentences cannot be filled in is the gap in your PMF right now.

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