Email spam is the cheapest way of marketing. For the initial outlay of buying a list of email addresses (which are very cheap) and a mass-mailing program (I'm assuming you get get those for free). Once you have that, you just feed the spam program the list of email addresses and the spam you want to send and let it do it.
Even if one in 100,000 emails results in a sale, they've made a profit. And there are always gullible people who will beleive anything that comes into their email box.
Well, then, those programs should suddenly get REALLY expensive and kill spam. 






