The latest numbers from Nielsen Online indicate that Twitter grew an unbelievable 1,382% in one year -- from February 2008 to February 2009 -- with over 7 million unique visitors in the United States. From January to February in this year alone, Twitter grew from 4.5 million to 7 million visitors, a 50% increase.
Meanwhile, Facebook, with 65.7 million unique visitors, increased its lead on MySpace, with 54.1 million visitors.
According to Adam Ostrow, writing on Mashable:
"While Facebook remains several orders of magnitude bigger [than Twitter], its recent move to a real-time homepage and its overhaul of Facebook Pages is seen by many as a move to thwart Twitter’s continued growth. It will be a few months until this shows up in the numbers and gives us some sort of indication as to whether or not that strategy is working, but for now, both networking sites are enjoying tremendous growth."