Turbine's free-to-play relaunch of Dungeons & Dragons Online - Eberron Unlimited - has attracted one million players and boosted revenues by a whopping 500 per cent.
Traditional subscriber numbers have also doubled since the September 2009 launch, GamesIndustry.biz reports.
"The response from players to DDO Unlimited has been nothing short of phenomenal," said Turbine president Jim Crowley.
"We've known all along how great this game is and by implementing an innovative new model that put the players in charge of how they pay and play DDO Unlimited, we've successfully expanded our reach and injected new energy into the game."
The sale of content through microtransactions in Turbine's digital store are three times the industry average, according to Turbine.
"The launch of DDO Unlimited has been a huge success and has really taken the game to a new level," added Fernando Paiz, executive producer.
"As we celebrate our fourth birthday, the game has never been better and we're just getting started with more adventure packs, more store items, and other innovative features coming in the major updates we have planned throughout 2010."