Mobile gaming, although growing, is locked into a model with an increasingly limited upside. Last year, mobile gaming in the United States generated $453 million in subscription and transactional revenue, up from $321 million in 2005. However, this growth is a result of overall subscriber growth—not a greater percentage of mobile users downloading games. According to the Yankee Group 2006 US Portable/Mobile Entertainment Survey, in the United States, 68.5 million mobile users reported playing mobile games. Of these, 11% downloaded additional games to their phone. This is the same percentage of mobile users who downloaded additional games in 2004.