clipped from: www.miamiherald.com   

BizBytes 101 Tip: Don't sign up for every affiliate network on the Web. Research what companies are advertising through a network you're interested in and check out what they're offering. If you're selling babysitting services on your site, for example, you wouldn't want to promote a product or service related to auto repair. Look for ads your users will find useful and be likely to click on to make a purchase, generating extra income for you.