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Performance & Measurement

CPA — Cost Per Acquisition

CPA — Cost Per Acquisition

CPA — Cost Per Acquisition

3 min read

CPA, or cost per acquisition, is what you pay on average to win one conversion — a sale, signup or lead. It is one of the clearest bottom-line efficiency metrics in advertising, and it is the target many automated bidding strategies are built to hit.

How CPA works

How CPA works

Define the action. Decide what counts as an acquisition.

Track conversions. Count how many of those actions your ads drive.

Divide the spend. Total cost divided by conversions is your CPA.

Set it as a target. Bidding can then chase that cost automatically.

What drives your CPA

What drives your CPA

Conversion rate. A better-converting page lowers cost per action.

Bid and competition. Auction prices push CPA up or down.

Targeting quality. Reaching the right people converts more cheaply.

Creative strength. Ads that resonate earn cheaper conversions.

Why it matters

Why it matters

Profit check. CPA against customer value tells you if spend pays off.

Bidding target. Target-CPA strategies optimise straight to it.

Comparability. It compares efficiency across campaigns and channels.

Challenges and considerations

Challenges and considerations

Value blindness. CPA ignores how much each customer is worth.

Attribution dependence. Your CPA is only as honest as your attribution.

Volume trade-off. A very low CPA target can starve reach.

Delayed conversions. Late actions can make early CPA look worse than it is.

Run this with your AI assistant — not another dashboard.

Run this with your AI assistant — not another dashboard.

OpenAds connects your assistant to every major ad platform, so you can plan, launch and optimise campaigns in plain language — approving the moves that matter.

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