Cost per Acquisition (CPA)
The average amount you pay to win one new customer or complete one desired action.
Cost per acquisition, or CPA, is what it costs you on average to turn a stranger into a customer — or whatever action you are paying for, like a sale, a booked call, or a signup. You calculate it by dividing your total spend on a campaign by the number of acquisitions it produced. Lower is better, as long as those customers are worth more than they cost you.
CPA is closely related to customer acquisition cost (CAC), and people often use the terms loosely. In practice, CPA usually refers to a single campaign or channel's cost per action, while CAC looks at the fully loaded cost across all your marketing and sales. Either way, the point is to compare that cost against what a customer is actually worth.
Why it matters
Knowing what a customer costs to acquire — and comparing it to what they are worth — is the line between spending that grows the business and spending that quietly drains it.