Definition
In a CPA deal the advertiser pays only for results. An affiliate network or an advertiser publishes an offer with a payout per action; a media buyer sends traffic to it from sources priced per impression or per click; the buyer earns the difference between payouts received and media paid. The same figure, cost ÷ conversions, is how any performance campaign is judged, whatever the traffic was bought on, which is why "CPA" is used both for the model and for the metric.
Formula and a worked example
CPA = total media cost ÷ conversions
Margin per conversion = payout − CPAA buyer spends $480 on popunder traffic bought at CPM and records 600 sign-ups on an offer paying $1.20 per sign-up. CPA = $480 ÷ 600 = $0.80; margin per sign-up = $0.40; total margin = $240. Sources whose own CPA exceeds $1.20 lose money and are blacklisted; the rest are scaled.
CPA variants
| Model | Action paid for | Typical verticals |
|---|---|---|
| CPL | Lead: a form or email submit | Finance, insurance, education, sweepstakes |
| CPI | App install, sometimes with a first open | Games, utilities, VPN |
| CPS | Sale, as a fixed amount or a percentage | E-commerce, nutra, software |
| FTD / first deposit | A first real-money deposit | iGaming, sports betting, trading |
| Revshare | A share of the customer's lifetime revenue | iGaming, dating, subscriptions |
SmartCPA and CPA bidding on ad networks
Some ad networks let an advertiser set a target CPA instead of a bid: the platform buys impressions or clicks on CPM or CPC behind the scenes and adjusts the bids per source toward the target, using the conversions reported by postback. This needs a working postback from day one and enough conversions per source for the algorithm to learn, which is why SmartCPA campaigns usually start after a manual CPM or CPC test.
Related terms
| Term | Relation | Where defined |
|---|---|---|
| Postback URL | How conversions are reported | Term page |
| CPM | How the traffic is usually bought | Term page |
| FTD | The iGaming CPA event | Term page |
| Affiliate marketing | The industry built on CPA | Term page |
FAQ
What is the difference between CPA and CPL?
CPL pays for a lead, a form submission or sign-up; CPA is the general term and can mean any action, including a sale or a deposit. In affiliate marketing CPL is one kind of CPA offer.
How is a CPA conversion tracked?
The ad network stamps a click ID on each click and passes it to the landing page; when the action happens, the advertiser or the affiliate network calls the network's postback URL with that click ID.
What is a good CPA?
One below the payout of the offer, with enough margin for the variance between sources. There is no universal figure; it depends on the vertical, GEO and offer.