"Many people have assumed that Twitter is just another social network, some kind of micro-blogging service, or both. It can be these things but primarily Twitter serves as a real-time information network powered by people around the world discovering what’s happening and sharing the news. The Iranian election was the most discussed issue on Twitter in the final year of a decade defined by advancements in information access. In the new year, Twitter will begin supporting a billion search queries a day."
— Why we can never rest: a year in the life of Twitter - Times Online