The numbers a board asks about. Six lessons on what it costs to acquire a customer, how long that takes to repay, what the customer is worth, where the margin goes, and which efficiency ratios mean anything.
| # | Lesson | The question it answers |
|---|---|---|
| 01 | CAC Payback, and LTV | What are the formulas, which assumptions are load bearing, and why is payback the honest number? |
| 02 | MRR, ARR and the Movements | How do new, expansion, contraction and churn build the revenue waterfall? |
| 03 | NDR, GRR and What Good Looks Like | What do they measure, how are they gamed, and what are real benchmarks? |
| 04 | Gross Margin for Software | What belongs in cost of revenue, including inference cost? |
| 05 | The Efficiency Metrics | Magic number, burn multiple and the Rule of 40: what does each one actually test? |
| 06 | LTV Over CAC Is Not a Strategy | What can the ratio tell you, and what do people wrongly conclude from it? |
Read 01 first. The other five assume its three load bearing assumptions are already visible to you.