They are middle to upper class teens and young adults who wern't tuff enougf to make it as punkers and to much of a pussy to pull off goth. I think It's kinda like if punk and goth had a baby but the mother did drugs and drank the whole time she was pregnant and Emo is the result of that. It's a fad for bord kids hailling out of the suburbian empire who have to much money and time on their hands(I am sure it's not cheap to be a posser ) and feel like their not getting enoughf attention from mommy and daddy so as a result they love bask in their imaginary melodrama and create shit to pretend be depressed about so they can play the part of the missunderstood abused victim and go write in their blogs and tell the world how hard their life is.
They spend a lot of money to look the part I.E. greesy blacked out hair, body peirceings(sometimes fake)a goth style make-up job, jewlery, but then spend their time crying and whineing about how hard it is to be them and how they don't fit in with anyone and about how no one understands them and the way they feel about things and cry because no one loves them their not punk and their not goth neither group wants to claim it because it's so lame so they call themselfs "Emo".