Answer:
cost per click (CPC) or pay per click (PPC) pricing, the name depends on who provides the service, but the concept is the same.
Explanation:
Companies that use pay per click (PPC) advertising will pay each time a user clicks on their ads to see them. When you open a website there may be several (sometimes more than a dozen) of different advertisements, but the advertiser companies only pays when someone actually clicks on the ad. PPC is the most popular and common advertising in websites and search engines, e.g. Google Ads works this way.