Why Spammers Send Spam

Well, duh, they make money:

“With the near-zero cost of sending out huge volumes of spam, the fact that more than one in ten users are purchasing products is clearly continuing to drive the economics of spam,” said Radicati.

Another way of looking at this is that a lot of folks consider the unsolicited email proffering painkillers, stiffeners, low interest mortgages, etc., to be as useful as other forms of advertising.