Today, the NPD Group released its annual report on online gaming in the US. The survey of 20,000 respondents aged 2 and up* was conducted from January 6-26 and measured Internet-enabled gaming on all consoles, handhelds, and PCs.

　　[UPDATE] "We start with the pool that play games (61 percent of population ages 2 and over)," NPD analyst Anita Frazier explained to GameSpot. "Of those, 57 percent play online. Of those that play online, 87 percent use a PC to play games online (folks can use multiple systems so it adds up to more than 100 percent)."

　　Overall, the study found that combined online gaming has risen dramatically, up 25 percent over the year prior, which itself saw a 19 percent bump on 2007. Surprisingly, though, it also discovered that despite the burgeoning popularity of massively multiplayer online games, PC online gaming was "slightly" down from the year prior. However, NPD did not say exactly how much the decrease was.

　　Less shocking was the increase in console online gaming. Aided by Microsoft's heavy support of Xbox Live, some 50 percent of online gamers used Xbox 360s to play games via the Web--a privilege that gamers must pay $50 a year for. Despite its use of cumbersome friend codes, Nintendo's Wii was in second with 29 percent, a sharp jump from 18 percent the year prior. In third place was the PlayStation 3, which 20 percent of those surveyed used to game online. No portable percentages were made public.

　　The only demographic group that NPD released hard numbers on was for respondents aged 13-17, whose online-gaming use grew from 17 percent in 2008 to 22 percent in 2009. The industry-research firm also noted a small downturn in online play for gamers aged 18-34 and 35-54, but did not release specific percentages.

　　NPD was also vague when referring to downloadable content. Its survey found that Xbox 360 and PS3 owners downloaded more content than other console owners, and their favorite type of DLC was expansion packs. That fact made ironic NPD's findings that DLC consumption had slowed overall, given that the survey was conducted before the release of the year's most popular digitally delivered expansions, Fallout 3: Operation Anchorage (January 27) and Grand Theft Auto: Lost and Damned (February 17). Wedbush Morgan analyst Michael Pachter believes that the latter expansion has already sold more than 1 million copies, and will go on to sell 2 million by year's end.

　　*=Respondents under age 12 had their answers submitted by their parents.