CPA stands for cost on acquisition. Namely, only when the money is paid advertiser of this method earn something. Mean business on the site and contributing to various different. The acquisition may fill out a form by the users. to download a movie or buy a product. CPA is the best way of payment for the ad is because the amount only when a fee payment that does not reach their goal. For this reason, this type of the worst, for the publisher is because the only time that successful advertising is the cost. The publisher should have to rate of exchanges website, the amount of the attention. something that most publishers can't . This type is usually by the advertisers banner is not used, but rather more with Affiliate Marketing, the best.