Product-market fit isn't a sudden switch but a palpable shift in momentum. As a founder, you feel the change from pushing against the current (hard selling with little traction) to suddenly being pulled by it (easier sales, inbound interest). This directional change in velocity is the clearest signal that you're onto something.

In fast-moving industries like AI, achieving product-market fit is not a final destination. It's a temporary state that only applies to the current 'chapter' of the market. Founders must accept that their platform will need to evolve significantly and be rebuilt for the next chapter to maintain relevance and leadership.

Product-market fit isn't just growth; it's an extreme market pull where customers buy your product despite its imperfections. The ultimate signal is when deals close quickly and repeatedly, with users happily ignoring missing features because the core value proposition is so urgent and compelling.

In a gold rush like AI, the shared 'why now' forces many founders into a pure speed-based strategy. This is a dangerous game, as it often lacks long-term defensibility and requires an incredibly hard-charging approach that not all teams can sustain.

The idea that startups find product-market fit and then simply scale is a myth. Great companies like Microsoft and Google continuously evolve and reinvent themselves. Lasting success requires ongoing adaptation, not resting on an initial achievement.

Unlike traditional software where PMF is a stable milestone, in the rapidly evolving AI space, it's a "treadmill." Customer expectations and technological capabilities shift weekly, forcing even nine-figure revenue companies to constantly re-validate and recapture their market fit to survive.

PMF isn't a fixed state achieved once. It's a continuous process that must be re-evaluated at every stage of growth—from $1M to $1B. A company might have PMF for one scale but not for the next, requiring a constant evolution of strategy and product.