Twitter traffic is up 700 percent over last year, and it’s all thanks to the old-timers. That’s according to the latest numbers from ComScore, which says Twitter drew almost 10 million visitors worldwide in February 2009. In the past two months alone, Twitter traffic has grown by 5 million worldwide visitors, while U.S. Twitter traffic accounted for 4 million visitors in February 2009—a 1000 percent jump over last year.