Customer acquisition cost

Customer acquisition cost is what it costs you, all in, to win one new paying customer. Take everything spent on sales and marketing in a period — ad budget, tools, agency fees, the salaries of the people doing the selling — and divide it by the number of customers who actually started paying in that period.

The word doing the work is "all in". Most people who quote a low acquisition cost are quoting ad spend divided by sign-ups, which is not the same measurement. If a salesperson on $6,000 a month closes twelve deals, that alone is $500 a customer before a single advert runs. Leaving salaries out does not make the business cheaper to run; it just makes the number that guides your decisions wrong in the direction you would prefer.

Acquisition cost also rises as you scale, almost always. The cheapest customers — your existing audience, referrals, the people already looking for you — are consumed first. The next thousand cost more than the first hundred, which is why a channel that looked excellent at $2,000 a month can be unworkable at $20,000 without anything having gone wrong.

A concrete case: $9,000 of monthly spend across ads, tooling and a part-time contractor producing eighteen new customers is $500 each. If lifetime value is $1,400, the ratio is 2.8 — under the three most businesses want, which means the honest next move is raising retention or price, not buying more traffic.