Metrics

CPA (Cost Per Acquisition)

The cost of acquiring one conversion, calculated by dividing ad spend by the number of conversions.

Cost Per Acquisition (CPA) measures how much you pay for each conversion. It's calculated by dividing total ad spend by the number of conversions. For example, if you spend €5,000 and get 100 conversions, your CPA is €50. CPA is often confused with CAC (Customer Acquisition Cost), but they're different. CPA typically refers to the cost per conversion from a specific campaign or channel, while CAC includes all marketing costs and measures the cost per new customer. CPA is useful for campaign optimization and comparing channel efficiency. However, it doesn't account for conversion value—a €50 CPA might be great if the average order value is €200, but terrible if it's €60. This is why ROAS (which accounts for revenue) is often a better metric for ecommerce businesses.

Related Terms

Frequently Asked Questions

What is CPA?

CPA (Cost Per Acquisition) is the average cost to generate one conversion, calculated by dividing total ad spend by total conversions. For example, €10,000 ad spend ÷ 200 conversions = €50 CPA. It's the inverse of ROAS—lower CPA means better performance.

What is the difference between CPA and CPC?

CPA (Cost Per Acquisition) measures the cost per conversion, while CPC (Cost Per Click) measures the cost per ad click. CPA depends on both CPC and conversion rate. For example, €2 CPC with 4% conversion rate = €50 CPA (€2 ÷ 0.04).

What is a good CPA?

A good CPA depends on your average order value and profit margin. If your AOV is €100 with 40% margin (€40 profit), you can afford up to €40 CPA to break even. Most e-commerce brands target CPA at 20-30% of AOV for profitable scaling, meaning €20-30 CPA for €100 AOV.

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