Cost Per Acquisition
Cost Per Acquisition (CPA) is the average amount spent to drive one desired conversion, such as a sale, sign-up, or subscription. It is calculated by dividing total campaign or channel cost by the number of conversions produced, showing how efficiently spend turns into the action a business cares about.
CPA is a core metric in paid advertising, where platforms let advertisers optimize or bid toward a target cost per action. The right CPA depends on the value of each conversion, so it is usually evaluated against margins or against Customer Lifetime Value.
A common pitfall is confusing CPA with broader Customer Acquisition Cost: CPA often covers a single channel or action and excludes salaries and overhead, while CAC captures the full cost of winning a customer. CPA measures converted actions, unlike Cost Per Lead.
Last updated: 14 June 2026