The Two Numbers

The only metrics that determine whether your startup lives or dies

by Lech Kaniuk

Every investor will ask about your unit economics. Most founders fumble the answer — not because their business is broken, but because they don't speak the language. LTV and CAC are not accounting concepts. They're a map of whether your business model actually works. This book walks through the math, the interpretation, and what to do when the numbers aren't where you need them to be.