Exactly six years ago, on March 21, 2006, Jack Dorsey, co-founder of Twitter, posted the first ever tweet. "just setting up my twttr," read the tweet from @jack. At only 24 characters, the first tweet was way within Twitter's 140 character limit, IBNLive reports.

The reason Jack Dorsey mentions Twitter as twttr is because that was the original code name for the project. The public launch of what was to soon become the world's most popular microblogging platform happened a few months later on July 15, 2006.

It took Twitter 3 years, 2 months and 1 day to reach the first billion tweets, and it took about 18 months for the first 500,000 users to sign up, The Next Web says,

According to eMarketer, Twitter’s advertising revenue is to triple by 2014, hitting over $540 million (up from an estimated $260 million this year).