A very interesting paper was published at Microsoft Research by Cormac Herley. It looks at the question “Why Do Nigerian Scammers Say They are From Nigeria?” and comes out with an unavoidable conclusion that that is by design.
Far-fetched tales ofWest 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 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
An interesting consequence of which is that even if only few people take the trouble to answer those scam letters but never actually go through with the money transfer, the Nigerian Scam would become prohibitively expensive to run.