Twitter turns 5, goes from 0 to 140 million tweets a day

NEW YORK (CNNMoney) -- Five years ago today, Twitter cofounder Jack Dorsey blasted off the very first tweet. What began as an experiment in "microblogging" -- no more than 140 characters, please -- has become a cultural landmark.

Twitter now has 200 million users, including tech luminaries, celebrities and the president of the United States. It started off slowly: In 2007, Twitter averaged just 5,000 tweets per day. But in 2009, the site hit a tipping point and became a broadcast channel for major news events.

http://money.cnn.com/2011/03/21/technology/twitter_turns_5/