Parks Associates estimates that microtransactions will overtake subscription models for MMO games going forward. They estimate that $6 billion will be spent on virtual goods by 2015.

“Gamers are investing real money in virtual items in Farmville, World of Warcraft, and other online games, to the point they are filing lawsuits to establish ‘ownership’ of these virtual goods,” said Pietro Macchiarella, research analyst for Parks Associates. “The enormous player base, availability on multiple devices, and the introduction of instruments such as Facebook Credits contribute to growing revenues.”

In their report Online Gaming: Global Outlook, 19 percent of active gamers spend money on in-game items, while online game subscriptions went down from 35 percent in 2008 to 28 percent in 2010. Companies like Zynga and Nexon have capitalized on this growing trend.

“It is becoming increasingly difficult to justify subscription fees,” Macchiarella said. “Thanks to social games and free-to-play MMOs, both casual and hardcore players have the option of playing quality games online for free. The virtual-items model that has proven so successful in Asia is finally generating significant revenues in North America.”