NO WAIT, OF COURSE THAT IS THE SINGLE MOST IMPORTANT SAAS METRIC

Summary from the TLDR Product newsletter

Each SaaS metric - whether retention, top-line growth, profitability, sales efficiency, LTV, Rule of 40, or NPS - holds unique value depending on the company's stage, market, and goals. Rather than rigidly focusing on one, companies should select metrics aligned with their immediate needs and growth objectives, balancing simplicity with clarity to guide team priorities effectively.