An online survey of "just over 20,000" U.S. residents found that the Xbox 360 accounted for 50% of consoles played online. The Wii made up 29%, a jump from 2008's 18%.

As for PC, NPD told Shacknews that 87% of those surveyed used a PC to play games online. That's down from 90% in 2008, described as a statistically significant decrease. This number presumably includes Flash-based casual games.

Specific figures for other platforms were not provided, but the company said that "PS2 fell dramatically and PS3 moved up from fifth place to third place."

The study further noted that micro-transaction downloads have slowed since last year's report, and added that Xbox 360 and PlayStation 3 owners engage in micro-transactions and purchase more downloadable content than those of other systems.

Overall, online console and portable gaming was said to have seen a "statistically significant increase," with 25% of those surveyed going online playing online with a console in 2009. That's up from last year, which only saw 19% play online.

Of the total online gamers, 22% were aged 13-17, an increase from last year's 17%. Meanwhile, the 18-34 and 35-54 year old demographics saw a decrease in usage, though exact figures were not provided.

Methodology
The report is based on online survey responses from just over 20,000 members of NPD's online consumer panel ages 2 and older (respondents age 2-12 were captured via surrogate reporting). Respondents had to personally play video games on a PC, video game system or device used for gaming. In order to qualify as an online gamer, respondents had to use one or more of the following systems to play games online: Nintendo DS/DS Lite handheld system, Nintendo Wii, PlayStation 2, PlayStation 3, Sony PSP handheld system, Xbox, Xbox 360 or PC. Both online gamers and gamers overall (whether online or offline) were included in the study. The survey data is weighted to represent the U.S. population of individuals ages 2 and older. Fieldwork was conducted from January 6-26, 2009.