Once product-market fit is achieved, the singular obsession must be retention. Before focusing on expansion metrics like NRR or efficient acquisition (CAC), you must first prove you can stop the "leaky bucket" and keep the customers you've already won.

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.

Scaling readiness is a sequential, two-step process. First, achieve Product-Market Fit, defined by customer retention. Only then should you focus on Go-to-Market Fit, defined by profitable unit economics. Scaling before proving both leads to failure.

The true indicator of Product-Market Fit isn't how fast you can sign up new users, but how effectively you can retain them. High growth with high churn is a false signal that leads to a plateau, not compounding growth.

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.

Founders often mistake $1M ARR for product-market fit. The real milestone is proven repeatability: a predictable way to find and win a specific customer profile who reliably renews and expands. This signal of a scalable business model typically emerges closer to the $5M-$10M ARR mark.

Sales are a vanity metric for product-market fit. The real test is having ~25 customers who have successfully implemented your product and achieved the specific ROI promised during the sales process. If you don't have this, you have a product problem, not a go-to-market problem.

The unambiguous signal of Product-Market Fit (PMF) isn't a magic number in your analytics. It's when customer pull becomes so strong that it breaks your supply chain, logistics, and team capacity, forcing uncontrollable growth even without marketing spend.

Successful founders can easily land initial customers and renewals through their personal network. This creates a dangerous false positive for product-market fit, masking whether the product has scalable value and can be sold by others without the founder's presence in the room.