Everyone knows that Nigerian scam e-mails, with their exaggerated stories of moneys tied up in foreign accounts and collapsed national economies, sound totally absurd, but according to research from Microsoft, that's on purpose. Computer World's Rohan Pierce directs us to the study, "Why do Nigerian Scammers Say They are From Nigeria," by Cormac Herley, principal researcher at Microsoft Research's Machine Learning Department.

As a savvy Internet user you probably think you'd never fall for the obvious trickery, but that's the point. Savvy users are not the scammers' target audience, Herley notes. Rather, the creators of these e-mails are targeting people who would believe the sort of tales these scams involve. (A 2006 New Yorker article by Mitchell Zuckoff offers a glimpse inside the mind of a scam victim.) As Herley explains, Nigerian scammers use what sounds like mathematic enforced game-theory that gives them the best odds through the use of these unbelievable tales:

Our analysis suggests that is an advantage to the attacker, not a disadvantage. Since his attack has a low density of victims the Nigerian scammer has an over-riding need to reduce false positives. By sending an email that repels all but the most gullible the scammer gets the most promising marks to self-select, and tilts the true to false positive ratio in his favor.
So, the more outlandish the story, the easier it is for the scammer to bypass skeptics and reach believers. Though it sounds counter-intuitive, when Herley explains it, the hyperbolic stories start to make sense.

An email with tales of fabulous amounts of money and West African corruption will strike all but the most gullible as bizarre. It will be recognized and ignored by anyone who has been using the Internet long enough to have seen it several times. It will be figured out by anyone savvy enough to use a search engine and follow up on the auto-complete suggestions [of search engines]. It won’t be pursued by anyone who consults sensible family or fiends, or who reads any of the advice banks and money transfer agencies make available. Those who remain are the scammers ideal targets. They represent a tiny subset of the overall population.
Gullible people take note: These scammers are inside your heads.