Generally, you don't make as much with affiliate (CPA) programs as you do with banner ad networks (such as FastClick, ValueClick, Burst!Media, Tribal Fusion, MaxOnline, Casale Media, and so on and so forth) that pay on a CPM or CPC basis.
The problem with the ad networks is generally you don't have a choice what ads you show, and most ad networks only want your U.S. traffic. For example, ad networks generally only fill 40 to 60% of your inventory. Therefore, it's good to daisy-chain ad networks together. You can do this because all the major networks allow you to set up defaults when they can't show an ad. At the last tier of your daisy chain, you should put banners to affiliate programs (such as via Amazon or those from Commission Junction) because they generally don't pay out nearly as much, and also because it is a guaranteed ad to show up.
It is possible, with a select few very good converting affiliate programs, to setup a mini-shop on your site, and really push one particular advertiser, and do pretty decently. The problem with that is you would really need to keep other advertising on the site to a minimum, and be selling products that are of direct interest to your visitors. Usually it's not worth the effort or risk IMO.
well i am planning on using amazon web api as my site's store so i do not risk loosing money if products dont sell. i am also taking up an associate account with Viz, LLC which is a publisher of anime/manga which is pointed directly at my site's audience. i think if i promote it well the store will do good;)
Good luck with it!! It's just that with associate programs such as Amazon, you only make money when you sell a product. With the banner networks, you make money for your traffic, each time an ad is viewed (regardless of whether it's even clicked on). That's why there's usually more money to be made there. But some affiliate stores do, indeed, do very well, if promoted the correct way.