CPC

What you pay for one click, set by the auction rather than by your bid alone.

A rising CPC is not automatically bad news — it often means you moved into more competitive, higher-intent queries. Read it next to cost per qualified lead.

The cheapest way to lower it is usually relevance: better match between query, ad and landing page.

CPC is the input everyone watches, but on its own it says nothing about whether the traffic was worth buying.