CPA

CPA (cost per acquisition, also called cost per action) is the average amount you pay for one completed conversion — a purchase, lead form, signup, call, or install — calculated as total cost divided by conversions. In Google Ads it underpins Target CPA bidding, where the system optimizes toward a CPA you set. CPA measures business outcomes rather than clicks, which makes it more decision-useful than CPC, though it stops short of profit; pair it with POAS or LTV for a full read.

Source: support.google.com