CAC Payback Period

This problem practices SaaS unit economics, especially how customer acquisition cost, monthly recurring revenue, and gross margin work together to measure how efficiently a company turns sales and marketing spend into recovered cash. In investment banking interviews, this kind of question tests whether a candidate understands the link between growth and profitability, and can explain why a shorter payback period suggests faster recovery of acquisition costs and a better path to scaling. Interviewers use it to see if you can think like an investor, focusing on the quality of growth, capital efficiency, and the timing of future returns.