ViralMarketing

This article doesn't get to the heart of it. But it's a start.

http://www.marketingsherpa.com/sample.cfm?contentID=2957

Viral marketing is basically auto-endorcing products. Products which you have to be telling people about in order to use. Such as email or other social software.

Maybe this :

• http://www.dfj.com/cgi-bin/artman/publish/stevetimmay97.shtml

• http://www.dfj.com/cgi-bin/artman/publish/steve_may00.shtml