This article must have been written with an implicit ARPU in mind. For lots of low ARPU companies, milestone 1 and milestone 2 are going to be inverted. That is, you'll likely get 10 paying customers before finding true product market fit.<p>Also, likewise, hundreds of customers will not equal $1M ARR for lots of SaaS companies. Even at 1000 customers, you'd need ~$100/mo or greater subscription price.<p>For SaaS companies with < $100/mo pricing, the equations and milestones are very different. For example, a $30/mo ARPU means having to get 3x more customers. So suddenly, hundreds of customers are not enough, you need thousands. That can mean the difference between a direct sales or white glove treatment to something slightly higher scale.
I enjoy reading how he quantifies pm fit - different people have different approaches. Another guy, can't think of his name, said 40%+ would be "very disappointed" if business shut down.
Think they're all useful signals.