# What is Product-Market Fit? Definition & Technical Mechanics

> **Source:** [SPIDITS AI Startup & Venture Intelligence Glossary](https://spidits.com/startup-glossary)  
> **Category:** Ecosystem  
> **Canonical Citation:** [https://spidits.com/startup-glossary/product-market-fit](https://spidits.com/startup-glossary/product-market-fit)

## Definition
Product-Market Fit (PMF) is the stage where a startup has built a product that successfully satisfies a strong market demand in a scalable way.

## Architectural Mechanics & Deep Dive
Product-Market Fit (PMF) is the stage where a startup has built a product that successfully satisfies a strong market demand in a scalable and repeatable way. Coined by Andy Rachleff and popularized by Marc Andreessen, achieving PMF is the primary milestone of early-stage startups. PMF is characterized by rapid user growth, high customer retention, and organic word-of-mouth traction.

## Industry Applications & Real-World Use Cases
Startup validation milestones and growth analytics

## Frequently Asked Questions

### How do you measure product-market fit?
High organic user retention (flat cohort curves), strong Net Promoter Scores (NPS), and customer demand outpacing production.

### Why is PMF critical?
Startups that scale marketing and operations before achieving PMF face high burn rates and eventual failure due to poor customer retention.

## Related Terminology
- [unit-economics](https://spidits.com/startup-glossary/unit-economics)
- [ltv](https://spidits.com/startup-glossary/ltv)
- [cac](https://spidits.com/startup-glossary/cac)

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*From the SPIDITS AI Knowledge Base (300+ terms indexed). Explore full technical definitions: [https://spidits.com/startup-glossary](https://spidits.com/startup-glossary)*