Cost Per Action (CPA) marketing, more often misconstrued by online marketing environments as cost per lead, is an internet marketing measurement and costing model for a given activity, such as a click-through, that generates revenue. It differs from traditional marketing metrics because instead of measuring a fixed amount per sale, the value of each action is measurable only after a deal is made. This type of marketing is referred to as an affiliate network or a pay-per-lead program. Affiliates help generate new leads and generate revenues for companies by providing specific services or products to customers interested in them through a CPA advertising campaign.