Pay per Call is one of the most popular advertising models. The whole point of it is that the advertiser pays according to the number of calls made by the users. Its very similar to the Pay per Click model; the difference being that rather than opening the advertisers website, the point is that the user has to make a phone call. The main advantage of the Pay per Call model is that it enables to customers to talk directly to the seller, before making the decision to buy the product/service. From the point of view of the affiliate partner, this model is good because it doesnt require the users to actually make a purchase. Instead, the affiliate partner gets money each time a phone call is made.