CPA (Cost per Acquisition) is total campaign cost divided by the number of conversions. It is one of the most important metrics for evaluating ad efficiency. A good CPA depends on industry, average order value, and profit margins.
You spent EUR 1,000 on Meta Ads this month and got 80 orders. Your CPA is EUR 12.50 per order. If the average order value is EUR 50, you have a ROAS of 4x.