Pokemon _was_ something new. New things can often fail hard or are major successes. Ex: Wii vs PSP-GO
Original Pokemon hit the imagination and the obsessive compulsion man kid gamers have (some adults too I guess). Not to mention is a portal and very casual game. All the ingredients for a must buy game. Pokemon has been riding that wave ever since. New gimmicks, re-makes, and cartoon tie-ins have tried to keep the wave going, but the sales have never been as good as the originals.











