Product-market fit (PMF)

The point at which you have built something a specific group of people genuinely want, evidenced by their behaviour rather than their compliments.

Example

Users return unprompted, tell colleagues, and complain loudly when it breaks.

Important

PMF is not a score and not a single moment. Retention, organic growth and how hard people fight to keep using it are the honest signals.

Related terms

• Retention — The share of customers still active after a given period. The inverse of churn, and usually the more useful way round.
• Startup — A new company built to grow fast by finding a repeatable, scalable business model. The defining feature is the search for scale, not the age of the company or whether it uses technology.
• ICP (Ideal Customer Profile) — A precise description of the customer who gets the most value from your product and is easiest to reach, sell and keep.
• Series A — The round that funds scaling a business model that already works.

Lessons that explain it

• Uncertainty and rejection — Practical founder psychology, not therapy. Rejection is the job's raw material, and uncertainty never resolves — you get better at holding it. (10 min)
• Knowing when to change direction — Persistence and stubbornness look identical from the inside. Deciding in advance what would change your mind is the only reliable defence. (12 min)
• What investors are actually assessing — Team, market, traction, insight, and whether the outcome can be large enough. In roughly that order, and mostly in the first ten minutes. (10 min)
• Evaluating an idea honestly — Nine dimensions, assessed as evidence rather than as a score. What you know, what you assume, and what is still unvalidated. (15 min)
• Competition and defensibility — Everyone has competitors, including spreadsheets and doing nothing. What matters is why you win a specific segment, and what stops a copy. (12 min)
• Entering another country — Usually later than founders think, and usually harder. What has to be true before it is worth the distraction. (12 min)

All 176 terms in the Founder glossary