What is market fit?
Market fit is the degree to which what a business offers matches what a specific market wants, values and will act on. The term is most often used as shorthand for product-market fit, a phrase popularised in the startup world to describe being in a good market with a product that market wants. In practice "fit" can be read at several levels: the problem, the product, the purpose behind it and the promise the brand makes in public.
The three fit stages
| Stage | Typical moment | The question it answers |
|---|---|---|
| Problem-market fit | Pre-seed, or before you build | Is the pain real, and do enough people have it? |
| Purpose-market fit | Seed, where product-market fit lands | Is it clear why you, why this, why now and why us? |
| Promise-market fit | Series A and beyond, or any business with a public reputation | Does the market believe what you stand for, and does your outward work live up to it? |
What is purpose-market fit?
Purpose-market fit is narrative clarity at the founding stage. Sightbox frames it as four questions that together form a Conviction Compass: why me (lived experience or authority in the problem), why this (why this shape of solution beats the workaround), why now (timing and the cost of inaction) and why us (who is invited to believe, and the belief they share). Purpose-Market Fit™ is a trademark of Sightbox Studios LLC.
What is promise-market fit?
Promise-market fit is reached when the market repeats and believes your promise in its own words. It is built in three layers: Focus finds the promise and writes it down, Form builds it verbally and visually, and Fit takes it to market and grows belief.
How is promise-market fit scored?
With the Promise Index: a score from zero to one hundred measured against the company's own promise sentence, not against an industry average. Four readings of twenty-five points each move from presence to coherence to ownership to belief.
| Reading | What it checks | Bands |
|---|---|---|
| Coverage | Does the promise appear on every surface, for who uses, who pays and who spreads? | Absent, Partial, Broad, Saturated |
| Consistency | Is the wording the same across surfaces and over time? Drift is the finding. | Fragmented, Loose, Aligned, Locked |
| Distinctiveness | The swap test: does the sentence still work with a competitor's name in it? | Generic, Familiar, Differentiated, Ownable |
| Resonance | Only arm's-length, verbatim evidence of the market saying it back. Reach numbers do not count. | Silent, Parroted, Adopted, Championed |
Totals band as Stated (0 to 25), Surfacing (26 to 50), Coherent (51 to 75) and Believed (76 to 100). A reading ends in one number, one diagnosis and one move.
Three beliefs behind the method
- You do not get to grade your own paper. The score comes from public surfaces anyone can check.
- Trust rests on your ability to check. Every score carries one line of evidence.
- Honesty is the pitch. Sightbox scored its own old website 29 out of 100.
Keep reading
- Message-market fit vs promise-market fit
- How to write a brand promise statement
- Product-market fit vs brand market fit
- How to measure market fit for a small business
- Market fit audit checklist
- How personal brands find market fit
- Free market fit self-score
- Sample Market Fit Read (fictional company)
Questions
Is promise-market fit the same as brand-market fit?
They overlap. Brand-market fit is a loose, general term for how well a brand resonates with its market. Promise-market fit is narrower: it measures your public presence against one written promise sentence, and only counts the market's own words as proof of belief.
Do I need product-market fit first?
Usually yes. Promise-market fit is the stage after product-market fit. A young company scoring Silent on resonance is on schedule, not failing.
Who created the Promise Index?
The Promise Index is part of the Sightbox method from Sightbox Studios LLC.