# CPA

> Cost per acquisition — the average ad spend required to produce one conversion, calculated as ad spend divided by the number of conversions of that type.

**CPA** (cost per acquisition, sometimes "cost per action") is the average ad spend required to produce one conversion — ad spend divided by the number of conversions of a given type. It is the headline efficiency number most advertisers optimize toward: a lead, a sale, or a signup, and what each one costs.

## How AnyTrack reports CPA

AnyTrack does not expose a single blended "CPA" column; instead the [Campaign Report](/docs/advanced-options-campaign-report#available-metrics) breaks cost down *per conversion type* — Cost per Lead, Cost per Purchase (CPP), Cost per Complete Registration, Cost per Add to Cart, and so on — each computed as total ad spend divided by the count of that event. Because those conversion counts come from AnyTrack's server-side integrations (not just the ad platform's pixel), the resulting per-acquisition cost reflects conversions the browser would have lost.

## CPA vs CPC vs CPM vs ROAS

- [CPC](/glossary/cpc) — the cost of one click, an upstream traffic cost; many clicks typically precede one acquisition.
- [CPM](/glossary/cpm) — the cost of 1,000 impressions, an ad-delivery cost; CPA measures the cost of the outcome, not the delivery.
- [ROAS](/glossary/roas) — the inverse perspective: ROAS measures revenue *earned* per dollar, while CPA measures cost *paid* per conversion.