What is a 'Core' Gamer? Is it defined by how much time you spend playing? How much money is spend on this hobby? Is it determined by what types of games are played?
I see speedrunners spend hours a day playing Mario, Metroid, Zelda and the like. If there is such a thing as 'Core' Gamer, I think speed runners can be counted as 'Core' Gamers more then anyone.