CPC, cost per click, is total ad spend divided by the number of clicks it produced. It is the core efficiency metric for performance media bought on a click basis, linking spend to the first measurable action a user takes.
Why it matters for agencies
CPC sits between CPM and CPA in the funnel — roughly CPM ÷ (CTR × 10). A rising CPC usually signals falling click-through rates or more auction competition. CPC is only meaningful next to the conversion rate behind the click: cheap clicks that never convert cost more than expensive ones that do.
Run the numbers with the free CPC calculator.