Could Social Media really predict the outcomes of an election?

The Huffington Post wrote an article referencing a map from the Oxford Internet Institute, that indicates that Obama has been mentioned on Twitter more frequently than Mitt Romney, and that this tells us Obama will win the election. This is an interesting one, because how can simple mentions indicate who is leading? People will often negatively mention someone on social media, and if a topic raises enough passion and or ire in people, then they could be discussing the fact they don't want a candidate to win. It also doesn't take into consideration the number of voters who don't use social media.

Social Media isn't as well used by the older generation who usually have very different views to the younger generation who are much more heavily using social media. All that being said, I'll be closely watching this and future elections to see how effectively this kind of statistical measure is in predicting elections.