CPM vs CPC vs CPA
CPM charges for impressions, CPC for clicks, CPA for conversions. Each step down the list moves risk from buyer to seller, and sellers price that risk in. The model you are billed on and the outcome you optimize toward are separate decisions: most social media is billed CPM regardless of objective, and a campaign optimized to conversions on CPM billing behaves differently from one bought on a true CPA deal. Compare channels on effective CPM and effective CPA, computed from spend and results, regardless of how each was bought.
| CPM | CPC | CPA | |
|---|---|---|---|
| You pay for | 1,000 impressions served | Each click | Each defined conversion |
| Risk sits with | Buyer | Shared | Seller |
| Native to | Display, video, CTV, most social, audio | Search, shopping, some social | Affiliate, some lead networks, rare direct deals |
| Good for | Reach, awareness, frequency | Traffic, consideration | Direct response with reliable tracking |
| Weakness | Pays for unseen and unclicked ads | Pays for accidental and bot clicks | Scarce, expensive, and subject to attribution disputes |
Terms in this comparison
Cite this page:
Agency Echelon. "CPM vs CPC vs CPA." Agency Echelon Reference, reviewed September 2026. https://agencyechelon.com/reference/compare/cpm-vs-cpc-vs-cpa/