Most affiliate program providers seem to be in love only with banner advertising at your Web Site, which is not necessarily the best way to go. Banner ads get a small amount of traffic and sales generated from them. Consider this when you are choosing an affiliate program. Make sure that you have a good selection of products to choose from. If you are selecting more than one affiliate program, make sure they fit together logically, i.e., don't sell flowers and hunting gear.
Many programs being offered up today are two-tiered.
This allows you to get paid off the efforts of others that you sell to. Include in your portfolio a few big ticket items. You don't need to sell a ton of those to make a couple hundred dollars. Be wary of signing up for every program under the sun and hoping that a few will work out. Even though most of them are free, the cost in your time and lost customers is tremendous.