---
title: "Product-Market Fit is No Longer Static"
description: "Between 2021 \u0026 2024, classic software companies lost their product-market fit overnight. In the AI era, PMF is like United Miles—you must continuously re-earn it to maintain status."
categories: ["AI","startups"]
keywords: ["product-market fit","PMF","AI","startups","Steve Blank","Four Steps to the Epiphany","forward-deployed engineers","continuous re-calibration","United Miles analogy","Polymarket"]
ai_summary: "AI's rapid evolution means product-market fit must be constantly re-established. Like United Miles 1K status, companies must continuously fly to maintain PMF as platforms evolve beneath them."
date: 2025-10-23
lastmod: 2026-07-31
canonical_url: https://www.tomtunguz.com/product-market-fit-not-static/
author: "Tomasz Tunguz"
---


> There's this notion that product market fit is this binary condition that once you pass the gate, you're done. And that's no longer the case. Product market fit is like United Miles. You continue to fly to maintain 1K. And we saw it between 2021 and 2024, companies that were classic software companies literally overnight lost their product market fit. And that'll be very much the case.

AI is changing what the market wants & what's possible so quickly that PMF is no longer static.

I discussed this idea on [TBPN](https://clips.tbpn.com/tomasz-tunguz-s3s39dq?episode=10-22-2025&name=Tomasz+Tunguz) with John & Jordi.

{{< youtube _0SJe7GXi1c >}}

I remember reading Steve Blank's [_The Four Steps to the Epiphany_](https://www.amazon.com/Four-Steps-Epiphany-Steve-Blank/dp/0989200507) in 2005. It established the idea of product-market fit. The magical moment customers pull your product into the market, & the playbook by which to develop it.

In the previous era, once PMF was established, it was taken for granted that it would continue. The underlying technologies advanced incrementally.

AI models & their capabilities evolve so quickly today that product market fit must be constantly re-established.

{{< email_image src="mebbhdxu1mqslj3dwyxk" alt="Screenshot 2025-10-23 at 8.34.26 AM" width="540" height="360" >}}

[Polymarket](https://polymarket.com/event/which-company-has-best-ai-model-end-of-2025) predicts Google will have the best AI model at the end of the year. At the beginning of 2024, Google was far behind. The most advanced companies in AI are still jockeying for position & so are startups.

This is one reason for the boom in [deployed engineers](https://tomtunguz.com/fde-cs/)—teams need people working directly with customers to understand these dynamics in real time. The velocity of change demands constant feedback loops.

Product-market fit is not a one-time event. As the technology changes rapidly underneath, so must your product.