Check here the latest figures for Twitter. It is definitely revolutionizing the way people communicate with each other. Twitter-revolution? Yes indeed.
Also note that 50% of the entire US population has a twitter account, followed by Brazil (9%), UK (7,2%), Canada (4,35%) and Germany (2,49%).
The White house has more than 2 million followers, which makes it the most followed public institution.
Young people under 20 years old use more Twitter than regular email or SMS for daily messages.