Many founders mistakenly define Product-Market Fit by revenue (e.g., "$1M ARR"). The correct measure is the ability to predictably create customer value. This is best quantified by a leading indicator for long-term retention, not sales figures, as revenue can be achieved without true market fit.

The founder realized his product was essential when the customer Slack channel blew up with urgent feedback during their month-end close. This intense, demanding engagement signaled deep user reliance, unlike the 'empty platitudes' from users of a non-essential tool.

When a product addresses a significant need, early adopters will actively help you fix bugs and overcome hurdles. This intense engagement, despite product immaturity, is a powerful indicator of product-market fit. Users are willing to go "above and beyond" because the outcome is so valuable to them.

PMF is not a one-time achievement; it is a moving target that changes as a company scales, competitors emerge, and user needs evolve. Teams, especially in large organizations, must continuously re-run PMF surveys to avoid complacency and ensure the product remains essential.

Founders often deceive themselves about having product-market fit (PMF) after landing a few customers. Replit's CEO clarifies that true PMF is unmistakable: it's when the market is pulling the product out of your hands so fast that you can't even provide it quickly enough. It's a feeling of explosive, overwhelming demand.

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.

Initially, customers often "round down," focusing on missing features. A key sign of product-market fit is when they start "rounding up"—their faces light up in demos, and they imagine the product's future potential, forgiving current limitations because they believe in the core value.

The ultimate test of PMF isn't surveys or usage metrics, but how indispensable your product is. If customers don't immediately notice and complain when it's gone, you haven't achieved true dependency. It's a visceral, high-signal test for any founder.

Superhuman's Product-Market Fit engine advises completely ignoring feedback from "not disappointed" users. This counterintuitive strategy prevents teams from being distracted by requests for features that are unlikely to ever convert detractors into fans.