Writing for USA Today, Jon Swartz covers the popularity of casual games on social media sites and how it might be indicative of a changing game market in the U.S.  The social game market is estimated at $500 million to $600 million.  Swartz talks to Think Equity analyst Atul Bagga, who sees that market doubling in 2010.

The movement is seen as in part driven by major game makers who ushered in casual games into the core game market, such as Nintendo Wii and Activision’s Guitar Hero.   Bagga says that while Wii set the stage and democratized social gaming, the internet opened it up to many who wouldn t normally play games.  Swartz points to gaming as the most popular category on Facebook and MySpace.  Currently eight games on Facebook have more than 12 million monthly active players, what Swartz cites as a bigger audience than World of Warcraft paid subscribers.  Most social games use a free-to-play model, and the head of one social media site estimates that popular games can generate as much as $5,000 a day.

Swartz’s piece highlights Zynga, Playdom and Playfish as three game makers currently dominating social media games, revealing their audience metrics and top games.

Read more at USA Today {link no longer active}.