Getty ImagesThe joystick generation is growing fast.
A new report finds that the video game playing population of the United States now totals 135 million -- a 140 percent increase over the amount recorded in 2008.
Those players put in over an hour a month on a wide variety of titles, according to research firm Parks Associates. The biggest draws are free-to-play and social network games, titles that spread beyond consoles and hefty PC rigs and onto the web and smartphones, among other platforms.
Nearly 80 percent of all U.S. gamers play either free-to-play online games or Facebook games, the study found.
[Related: The dark side of free-to-play games]
Tablets were the big wellspring of gamers, with 71 percent of adult owners and 79 percent of teen owners saying they played games on the systems.
Retailers, though, might not be thrilled about the surge of new players, as the report reiterates the oft-stated comment that the age of digital distribution is coming fast.
"Online, and especially mobile, gaming is transforming the industry, changing it from one focused essentially on packaged goods sold at retail to one that provides services to consumers," it reads.
Free-to-play games are lowering the cost of entry, which is giving a lot of fence sitters a nudge. The games don't stay free for everyone, though. About 5-10 percent of the player base of social and free-to-play games regularly pay out of pocket to keep the fun going. The average Facebook gamer who does spend money on those games shells out about $29 per month, according to the report. Meanwhile, those who pay for virtual goods and upgrades in free-to-play games average about $21 dollars per month.
Mobile games, of course, continue to grow as well. About 18 percent of all gamers download titles to their phones versus just 7 percent in 2008. And just as the user base is growing fast, so too are the revenues.
"Mobile games can yield high amounts of spending per user," says the report. "In particular, most of the top 25 grossing games on both iPhone and Android devices can be
downloaded for free. In this way, mobile gaming is poised to expand U.S. gaming revenues over the next several years by processing hundreds of thousands of gameplay-related microtransactions for a broadening population of gamers."