Everyone with email receives the Nigerian email scam (also known as the “4-1-9” or “Advance free fraud” scheme); I receive a solicitation at least once a month, usually more. As Douglas Cruickshank of Salon points out, the scam is more than 10 years old, with origins in the standard postal system (the USPS has a webpage to help recognize the physical scam letter).
I always assumed that the constant flow of email means that the perpetrators are still finding suckers, but I had no idea it was this bad: in the last year, 16 people were had for a cumulative $345,000.
Snopes has a well articulated history of the scam.