WHEN SHOULD STARTUPS PRIORITIZE PMF SCORE OVER NPS?

Summary from the TLDR Founders newsletter

Smart startups measure success differently at each stage of growth. Early on, use the Product Market Fit Score to ask "How disappointed would you be if our product disappeared?" This reveals if you've built something truly essential. Only after 40% of users would be "very disappointed" without you should you start tracking Net Promoter Score, which measures referrals. Following this sequence prevents the common trap of having customers who casually recommend your product but wouldn't actually miss it if it vanished.