SaaS investment is all about revenue and growth. VCs and gurus are focused on the top line. There is a strong belief that profits will follow in time. The big returns come from following the hockey stick curve. Metrics reflect the same thinking. LTV, ARR, MRR. Even churn is a number linked to the income line. Yet there are a couple of cost metrics that matter. Customer Acquisition Cost (CAC) is the top of this.