Why do Nigerian email scammers say they're from Nigeria?

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(CBS News) "Dear Sir/Madam" the emails usually begin. And then come the promises of quick money, the assurances that a royal family member will make good on the bargain (accompanied by numerous typos.) By now, everyone is familiar with "Nigerian scammers" - that brand of spam that seeks a cash investment and the promise of a big payday. But surely actual scammers would have realized by now that no one believes a Nigerian prince will offer up thousands of dollars to random strangers. According to new research, not only do scammers not worry about people being skeptical - they actively encourage it.

Microsoft researcher Cormac Herley looked into the matter and concluded, "Far-fetched tales of West African riches strike most as comical. Our analysis suggests that is an advantage to the attacker, not a disadvantage."

"By sending an email that repels all but the most gullible the scammer gets the most promising marks to self-select." Herley wrote.

This is why so many email scams claim to originate from Nigeria - though most spam emails come from elsewhere, including the United States. Anyone with any degree of familiarity with Internet scams will immediately close the email, leaving only the most susceptible victims to actually read its contents.

As Herley points out, "The scam involves an initial email campaign which has almost zero cost per recipient. Only when potential victims respond does the labor-intensive and costly offort of following up by email (and sometimes phone) begin."

It seems counterintuitive, but by being so obvious with their deception, scammers actually maximize their chance of making money. Since only the most gullible victims will respond, the chance that they will actually fork over money to the attacker increases.

Reed Cormac Herley's complete study HERE for more information (and the math to back it up.)