Playdom said it has raised $33 million in venture funding, presumably to continue the acquisition spree it has been on for the past year as it expands in social gaming.

Mountain View, Calif.-based Playdom has now raised a total of $76 million to date. New backers include Bessemer Venture Partners, Disney’s Steamboat Ventures, and New World Ventures.

Playdom was founded as YouPlus in 2008 by Dan Yue (pictured left) and Rick Thompson (pictured right). It tried to make games on Facebook at first but failed. Then it switched to MySpace and dominated the social network’s top 25 game ranks with titles such as Mobsters. Then it returned to Facebook, raised money and hired John Pleasants, Electronic Arts’ No. 2 executive.

Since that time, Playdom has become a player on Facebook with 37 million monthly active players, according to AppData, putting it behind only Zynga, Electronic Arts Playfish, RockYou, and Crowdstar. Its top titles include Social City, Sorority Life, Mobsters, Tiki Resort, Treetopia and the newly released Verdonia. To date, more than 130 million Playdom games have been installed on Facebook, MySpace, iPhone and Hi5.

Playdom has been making a string of acquisitions. The deals include the purchase of Acclaim Games, Merscom, Three Melons, Offbeat Games, Green Patch, and Trippert Labs. The company has well over 400 employees and recently expanded into Europe.