The NPD Group calculates that gamers in the U.S. spent some $15.39 billion USD on gaming-related content in 2013, a 1 percent increase from the annual sales figure recorded for 2012. It's still a sight better than the year-over-year declines suffered in previous years. What's interesting about this figure is that digital content accounted for around 47 percent of 2013's total video game sales.
Spending for physical retail products fell 11 percent year-over-year to $6.34 billion USD, while used game sales and game rental fees contributed another $1.83 billion USD. "Digital content acquisition" for 2013 rang in at $7.22 billion USD, and was the only portion of the market that experienced appreciable growth. According to NPD, 36 percent of U.S. gamers aged 13 and up turned to digital storefronts for their fix.
NPD hails this growth in digital spending as "vital to overall industry health." Note that NPD encompasses game downloads, subscription fees, expansions and DLC, and mobile and social sales under the growing digital umbrella.
(Image Source: GameStop)