Free-to-play games that generate revenue via microtransaction purchases are now common for PC and mobile phone gamers. However, the free-to-play concept has not gained much traction in the console game industry. That could be changing, however. This week, Microsoft announced that it would release the first Xbox 360 game that will use the free-to-play business model.The company announced on its PlayXBLA.com web site that it will release Happy Wars later this year. The downloadable Xbox Live Arcade game is a multiplayer action title from developer Toylogic that features " ... exciting castle siege and magic spell battle action for madcap free-for-all battles in fantasy world settings."The game will be free to download and play for Xbox 360 gamers who are subscribers to the Xbox Live Gold service. However, Microsoft adds that Happy Wars will let players " ... buy lavishly rendered items at the Item Shop etc. for your character to flaunt your originality on the field of valor."While this will be the first Xbox 360 game with this kind of microtransaction model, Sony has already released a few free-to-play games for the Playstation 3, including the first-person shooter No Man's Land earlier this year. Sony and developer CCP Games will also launch the highly anticipated sci-fi shooter Dust 514 as a free-to-play game later this year.