As someone already pointed out in this thread: Twitter and other new social networking mediums like it are simply additional vehicles to drive your messages home. Also, Twitter has several "addons", so to speak, that allow one to track metrics from alternate information delivery methods. Also, it allows us to reach the same audience in different ways, i.e.; through desktop applications like Tweetdeck or similar mobile apps.
UO, like all MMO's, is a social game which means it can greatly benefit from new social media, when leveraged correctly.