Affiliate programs are basically CPA programs. CPA stands for Cost Per Action where the marketer will earn when a visitor performs an action such as product purchase, sign-ups, etc. Affiliate programs or CPA programs are very different from PPC programs. PPC programs are Pay Per Click, where the marketer will earn for every legit click made by the visitors. You will earn from affiliate programs or CPA programs only when actions like product purchases are taken, however, you will earn from PPC whenever there is a legit click. There are affiliate programs based on PPC mode. In fact, I have once tried an affiliate program based on PPC model. This affiliate program paid 1 cent per click and 10 percent commission for product click. In other words, if your visitor clicked an affiliate ad, you would earn 1 cent right away, and if the visitor purchased a $100 product you would earn $10. I made some money through the clicks but there were no sales, therefore, I could not reach the payment threshold. I had to give up the program because of its high withdrawal threshold. I don't remember the name of the site. If you want to try the PPC program, why don't you try Adsense?