Cost Per Acquisition
Cost per acquisition (CPA) is the average amount you spend to generate one conversion, such as a sale, lead, or signup. It is calculated as total spend divided by total conversions. CPA is a core efficiency metric because it connects ad spend directly to business outcomes rather than clicks.
Why It Matters
CPA tells you whether campaigns are profitable relative to what a customer is worth. It anchors bidding decisions, budget allocation, and the go or no-go call on scaling a campaign.
Common Mistake
Judging CPA without knowing customer lifetime value or conversion quality. A higher CPA channel can be more profitable if it brings better customers, so cutting on CPA alone can kill your best source.