Pay-per-click (PPC) is an online advertising model in which an advertiser pays a publisher every time an advertisement link is “clicked” on. Alternatively, PPC is known as the cost-per-click (CPC) model. The pay-per-click model is offered primarily by search engines (e.g., Google) and social networks (e.g., Facebook). Google Ads, Facebook Ads, and Twitter Ads are the most popular platforms for PPC advertising.