CNN is reporting that Bill Gross’ UberMedia – home of several Twitter clients – is working on its own network as an alternative to Twitter. Though, says one of CNN’s sources (who have “been briefed” by Twitter), that may just be a backup plan if UberMedia’s fractious relationship with Twitter breaks down completely. UberMedia is reportedly in the process of acquiring TweetDeck, whose users automatically get a back-up network. That might be a way for UberMedia to ease into the business. Twitter claims 175 million users – although some think the active number is more like 20 million – its brand is huge and its APIs and streams are woven into the fabric of the social web. While Twitter is still struggling to build out its marketing platform, it has broadened its data and stream licensing through Gnip, MediaSift and Sulia. I doubt a few extra characters per Tweet is much of a reason for its users to switch.