This is one of the best articles I have ever read on MSNBC, which I normally avoid like the plague due to the terrible design of their Web site that loads pages so slowly with all their ads.
However, this article details the factors that perpetuate the evil of spam. But, legitimate businesses pay for leads from spam, and that is more than enough to continue the spam barrage. Also, ISPs just love to have spammers as clients as they typically generate monthly fees of many thousands of dollars.
MSNBC August 11, 2003