Twitter predicts the future?

Twitter, the group consciousness that it is, has been used to predict the future. Well, the future of the stock market. A researcher discovered that one could achieve an average return of 15% by following stock market tweets, buying and selling accordingly.

A similar study predicted the results of the German elections within a 2% accuracy compared to the numbers of votes received. If Twitter is capable of doing this, perhaps with some more analysis it might be capable of more. Is Twitter a 21st century crystal ball? We'll have to find out, or… Twitter will find out for us.