At this point, to me (this is not meant to apply to anybody else), I can't see a reason for getting either a tattoo or a piercing. Looking at it from a cost/benefits analysis point of view, it would hurt a lot (cost), so it would have to have a GREAT benefit to make up for that. And tattoos are so permament; what if I change my mind?
Thus, I can't think of any benefit that is great enough. Making a statement? At this point the only statement a piercing or tattoo makes is, "look at me, I can follow trends." Being individual? See previous comment. Rebellion? Against whom? Nobody is telling me not to. For the heck of it? Not nearly good enough to compensate for the cost.
Maybe I'm missing something?