CPA vs CPC

CPC prices a click; CPA prices a conversion. The bridge is conversion rate: CPA = CPC ÷ conversion rate. A $5.42 click at an 8.18% conversion rate implies a $66.26 cost per conversion. Optimize CPC for traffic, CPA for customers.

Anchors: $5.42 avg search CPC, 8.18% avg CVR▸LocaliQ · 2026 survey

CPC settles at gate two, CPA at gate four. Everything between them, landing page, offer, form length, load time, belongs to conversion rate. That is why the same traffic can produce two very different CPAs on two landing pages.

Broaden targeting and clicks get cheaper: say CPC drops from $6.00 to $4.00. But the broader audience converts at 4% instead of 8%. Before: $6.00 ÷ 0.08 = $75 CPA. After: $4.00 ÷ 0.04 = $100 CPA. Cheaper clicks, 33% more expensive customers. The inverse also holds: paying more per click for higher-intent traffic often buys a cheaper acquisition. Chase the metric your economics settle on, which is CPA for any account judged on customers rather than sessions.

• Optimize CPC when conversion tracking is unreliable or volume is too thin for the algorithm to learn on conversions.
• Optimize CPA (or Target CPA bidding) once you bank steady conversion volume and trust the tracking.
• Report both, one gate apart: rising CPC with flat CPA means intent quality improved. Falling CPC with rising CPA means you bought junk traffic.

Related: CPA vs CPM, the CPA formula, and the calculator.