Giant Realm, a New York City-based online ad network focused on video games, music and entertainment, has secured $3.5 million in funding, the company told us. The round was led by Comcast Interactive Capital, the investment arm of the cable operator. Edison Venture Fund, which providing an unspecified amount of seed backing when the Giant Realm launched last November, also participated in the current round. The William Morris Agency, another early backer, did not take part this time out.

So far, Giant Realm’s publisher group has attracted roughly two dozen entertainment websites in the areas of video gaming, indie music, film, and sci-fi to its network. The company cites comScore Media Metrix data that says Giant Realm’s network drew 3.75 million uniques in January. The proceeds of the funding will be used to build out its sales and marketing force. The rest of the funding will support Giant Realm’s efforts to develop more features on its main site.

• Games Media Properties Forms Giant Realm: Part Ad Network, Part Digital Entertainment Portal