Ten Things You Need to Know About Twitter

Launched as a side project only 3 years ago, Twitter.com has achieved the stratospheric growth and household-name recognition status that most online startups can only dream about.

Twitter is a social messaging utility that encourages users to answer the question, "What are you doing?" in a

maximum of 140 characters. The response to that question, which is called a Tweet, is then shared with a user's "followers," those who have opted to receive updates. As soon as Oprah sent her first Tweet in April 2009, the microblogging platform officially went mainstream. Even the Dalai Lama Twitters.

Here are 10 things you need to know to get up-to-speed:

1. Who Uses Twitter?

Twitter may have started as the dominion of early adopters in the 18- to 24-year-old age group, but it's being used increasingly by a business demographic, with 3 mil- lion Tweeters aged 35-49 and 62% of total users accessing it from work. Mobile usage is also growing, with 735,000 unique users posting Tweets from mobile devices in February 2009.