The authors review 33 cases and related materials to understand how customer lifetime value (CLV) is taught. The authors examine (a) whether CLV is calculated using something other than contribution (e.g., revenue), (b) whether discounting is used, and (c) whether acquisition costs are subtracted before reporting CLV. The authors show considerable confusion in teaching materials; they contain incorrect formula, erroneous claims, and contradict other materials from the same school. The solutions that the authors offer should improve the teaching of CLV. The authors recommend educators always (a) use contribution margin, (b) discount cash flows, and (c) never subtract acquisition costs before reporting CLV.