CPA (Cost Per Action) is an online revenue model that is emerging as a pretty good alternative to the traditional Adsense and cost per sale options. CPA has been around for a while, but is now gathering momentum. What CPA Is – And A Look At Why It’s So Powerful Typically, how CPA works is as follows: 1. You have a blog about diets, weight loss, fitness. You have some traffic coming to it already which is interested primarily in losing weight. 2. You see that Product X which sells diet pills offers (for example) $50 per lead for every visitor you send them who requests a free trial for the product. 3. You join the CPA program, put up the banner for the free trial and let your traffic do the rest. This is exactly why CPA is so powerful. Your site visitor does not have to buy a thing in order for you to get paid. They only have to request the free trial and you get paid $50 (typically they would pay $3 or so for shipping – most people who have an interest in diet pills would willingly do so). If you've not tried CPA yet, you may benefit from it. There's some more free information about it on the blog.