Leader internet measurement firm comScore released on Friday new data that reveals the United States online gaming market attracted approximately 87 million visitors in May 2009, a 22 percent gain over May 2008. The data points to a slumping economy as a primary driver, as more and more Americans are increasingly seeking out cheaper entertainment options.

Coming up big again this year is Yahoo! Games, bringing home the bacon with approximately 19.4 million visitors, up 6 percent from May ’08, filing their way through the big Y’s offerings. EA Online took the number two spot with 18 million visitors, a healthy 34 percent increase YOY. Nickelodeon Casual Games with 14.8 million visitors, and Wild Tangent Network with 13.8 million visitors (a 16 percent increase) took spots 3 and 4 respectively. And while these numbers are in their own right, impressive, the best newcomer award clearly belongs to GSN Games Networks which saw 6 million visitors in May 2009, representing a stellar 563 percent increase over May 2008 traffic.

“Online gaming continues to be one of the top gaining categories over the past year growing at ten times the rate of the total U.S. Internet population and reaching nearly one out of every two Internet users,” said Edward Hunter, comScore director of gaming solutions. “And the growth in the category is occurring not only at the top gaming destination sites, but also through viral distribution platforms, including widgets and applications. In fact, some online gaming companies that distributed their games across sites are reaching as many people as the top online gaming sites.”

Also included in the data is comScore’s noting of a growing trend in the online gaming space: distributed content. These distributed content platforms include widgets and applications. comScore has found that these methods of distribution can often put creators of said delivery mechanisms numbers similar to gaming portal destinations. For example, accord to the comScore data, MochiMedia reached a combined total audience of 16.9 million in May ’09, which in effect, would put them in spot number 3, above Nickelodeon Casual Games. Likewise, Games2Win was visited over 1.8 million times in May ’09, which would put them squarely within the top 20 online gaming destinations.

“The power and reach of viral content distribution is well captured by comScore Extended Web Metrix,” said Alok Kejriwal, CEO and Co-Founder, Games2win. “With these latest consumer traffic numbers, we can now effectively present and strategically leverage our accelerating audience reach, and share data with our advertisers, marketers and partners that represents a holistic view of who is playing our games and from where.