Affiliate Networks and Affiliate Programs: Free Source to Make Money on Your Website 

Why use affiliate program networks?  1) A third party's tracking and monitoring may give you honest and relatively fair transaction results. 2) It's easier to find out and then participate in multiple affiliate programs with only one user name and password in a network. 3) It's possible to get paid faster 'cause some networks would pay you according to your total transaction amount with all affiliate programs you join within a certain period of time.

Why participate in different network?  1) You got much more choices than join only one. 2) Different affiliate networks may pay different commission rate on a same merchant's service or products, and you can always select higher commission links to put to work.  3) You would learn more from multi-networks 'cause they have different experience and may give you different support. 

clickXchange	It seems it's name says itself - clickXchange offers many pay-per-click programs, probably more than any other affiliate network.  As a bonus they will pay you $10 for each advertising member that joins. They charge no setup fee to advertisers so that many smaller merchants choose to advertise through it.
DirectLeads	This is a great affiliate network you can't afford to ignore at all.  It lets you choose the right offers to put in front of your right users at the right time, helping generate new subscribers and visitors for Advertisers. DirectLeads™ has an excellent  tracking system and online support, and pays commission according to your combined transaction amount from all merchants you join.
LinkShare	LinkShare is a network made up of merchants who offer affiliate programs and the affiliates who participate in those programs. With LinkShare, you may participate in multiple affiliate programs through one single interface, with one single username and password.  Sign up today to enjoy the benefits of partnering with over 500 top online merchants.