While AznHisoka has a point there - find the best program as far as commissions go - there is more to it. There is always a risk in affiliate marketing, and at

While AznHisoka has a point there - find the best program as far as commissions go - there is more to it. There is always a risk in affiliate marketing, and at this point I'd consider the major success differentiators to be 1) innovation and 2) risk mitigation. You can make a really innovative site and get lots of quality traffic, but you had better do your damnedest to mitigate your overall risk or you may find your source of revenue gone overnight. You can mitigate risk by spreading your site out so that it covers many products, brokering custom deals, making your own community (FatWallet.com and Extrabux are great examples), or doing something really innovative in terms of functionality (HipMunk, Mint.com). As an example of what can happen, we had an affiliate site running for the better part of 3 years on Google AdWords. We owned the top spots in a pretty significant vertical and made quite a lot of money. The client (the agency of record for the product) was super happy, we had exclusive terms and business was booming. All was well until one day I get a call. The merchant decided to drop the agency and eliminate their entire affiliate program. It didn't matter that we generated them huge sales each month, that was it. Nothing we said could convince them otherwise. That was it.