According to NPD, and their latest report, Core Gaming 2013, within the US population ages 9 and older, almost half play video games on core gaming device.
Only 14 percent, or 37.5 million people, would be considered a core gamer*
Ages 9-17 are most likely to be a core gamer (26 percent)
Ages 18-34 are the next largest group of core gamers (21 percent)
Over the past year
88 percent of core gamers state they purchased new physical games
78 percent purchased physical used games
70 percent purchased digital full games
*Core Gamers were described as playing Action, Adventure, Fighting, Flight, Massively Multi-Player, Racing, Real Time Strategy, Role-Playing, Shooter, or Sport games on a PlayStation 3, Xbox 360, PC or a Mac, and spending 5 hours or more per week gaming on any of these devices.