Twitter in US

sur eMarketer

eMarketer projects that the number of Twitter users will jump to 18.1 million in 2010, representing 10.8% of Internet users.

By all measures, Twitter is growing, and quickly.

comScore reported that Twitter.com drew 4 million unique visitors from home, work and college/university locations in February 2009, up from 340,000 a year earlier—a 1,086% increase.