Email Spam was invented by capitalists to make money out of the old dictum that "There is sucker born every minute." Americans are so gullible that many of them actually read Spam email.
Some companies do an awful job of controlling or trying to eliminate Spam. Hot Mail and Yahoo are both perfect examples. They must get a percentage of the profits that spam generates when the suckers answer it.
Remember: Fraud and Greed are the foundation of capitalism. Spam is part of their scheme to try to get their hands into your pocket book.