Customer acquisition cost

CAC is a simple ratio: total spend on acquisition activity over a period, divided by the number of new customers won in that period. The formula is easy. What's hard is being honest about what belongs in the numerator. Tool subscriptions are the visible part of that spend. Salaries, commissions, and the labor of actually running the acquisition motion are usually the larger part, and they're the part most CAC calculations quietly leave out.

What actually goes into the number

For an outbound-driven motion specifically, the full cost stack runs across a few layers: data and enrichment for finding and verifying contacts, sending infrastructure for mailboxes and domains, deliverability monitoring to keep that infrastructure healthy, and the orchestration and labor to design and run the whole system end to end. A CAC calculation that only counts the first layer, the tool subscriptions, and skips the labor of running the waterfall and watching deliverability, understates the real cost of the customers it produced.

Fully-loaded CAC, spend plus salary and commission for everyone touching acquisition, tells a different story than marketing CAC, which counts program spend alone. Neither version is wrong on its own. But comparing a fully-loaded CAC at one company to a marketing-only CAC at another is comparing two different numbers that happen to share the same name.