Courtesy of a link provided by commenter William Ockham at The Passive Voice, I found a scholarly, rather technical and mathematical, but very interesting article titled ‘Why do Nigerian Scammers Say They are from Nigeria?‘ (link is to an Adobe Acrobat document in .PDF format). It’s from Microsoft Research, and analyzes how scammers operate and how they try to pick only the most gullible respondents.
The Abstract sums it up as follows:
Far-fetched tales of West African riches strike most as comical. 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 overriding 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.
There’s more at the link. Not casual or light reading, but interesting to those involved with computer security, or who want to understand how scammers make a living.