I know I'm fast slipping into old-fart-hood (if not already there), but I don't 'get' the videos' popularity -- they struck me as pretentiously pseudo-cool.
I love them, mainly because they're a really fun parody of the ridiculousness that their competitors often run (I'm looking at you Axe). They built a character that all at once oozes likability while at the same time pointing out just how stupid the whole idea that using a body-wash will get you laid is.
It may have been a stupid idea, but Axe got hundreds of thousands of prepubescent teenagers using deodorant...their deodorant. And men tend to stick with a brand once they are comfortable with it.