Understand the different sales models. The most common forms of paid channel advertising are cost-per-mille (CPM) and cost-per-click (CPC). CPM ads are the banners you see across the tops of webpages. You are billed a flat rate based on the number of times the ad is displayed. CPC ads are the paid advertising results you see on a Google search results page or in the side margin on a Facebook page. You pay for every click on your ad.