By now almost everyone that has an email account has been contacted by the Nigerian Minister of the Interior, or some other banker, deposed prince or government official with millions of dollars they want to launder.
Similar to the art scam which preys on our ego's, the Nigerian scam preys on greed. You might ask why these scammers continue to persist when almost everyone you know deletes the emails immediately?
It is a numbers game. These scammers send out five million emails a day. They only need to hook 3 or 4 people to make it pay off big.
The Ebola Monkey Man has an amusing website (not for the puritanical of mind) where he scams the scammers. This site is a wonderful way to waste an afternoon. Be prepared to laugh your ass off.