I guess it all depends on your definition of genius. A salesman who is smart enough to figure out how to sell people a load of crap could be called a genius ... and I kinda think if you look at it that way figures like Che or Hitler could be called geniuses. It doesn't necessarily mean they were good people.
Well, I wouldn't include good manipulative skills in genius. That's probably why you would say things like "he's a genius when it comes to selling things" or something like that. It indicates that it isn't the natural use of the word.
Hey, my friend is a genius at data entry. Absolute GENIUS. Don't be ripping on him, man.
