Who Rules the Web Now?

Harvard Business Review

They're out to kill the cost-per-thousand or CPM-based ad sales model. Instead, each possesses a wealth of user information to target ads to individual consumers on a cost-per-click (CPC) or cost-per-action (CPA) basis. In effect, they are turning online advertising into a lead generation play to deliver better ROI for marketers. Communication Internet CPA CPC[For more, visit the Communication Insight Center.].

CPM 12