First tweet sent five years ago

Twitter today celebrates the fifth anniversary of the first Tweet.

It was sent on 21 March 2006 by co-founder Jack Dorsey, simply saying "inviting coworkers." Since then, the microblogging service's rise has been meteoric, reaching an average of 140 million tweets per day.

Throughout its five years of existence, Twitter has also gained huge importance as a tool for communication, even as a journalistic hub, anytime political issues broke out. Iran was a clear case, and so have been the recent revolutions in North Africa and the Middle East.

A revolutionary way of communication for both the banal and the crucial, Twitter now faces two challenges: On one hand, coming up with a business model that turns the massive number of tweets into revenues and, on the other, serving as a tool for businesses to reach a greater audience. Check last week's feature on IT PRO to learn more about how five-year-old Twitter is doing on both of those aspects.

Fit for business or not, profitable as a business or not, the truth is, within five years Twitter has gone from being a San Francisco start-up with a big question mark to, we learnt from an article on The Wall Street Journal last week, declining offers for $8 billion to $10 billion. Why would they turn those offers down? Well, according to the WSJ, Twitter bosses are expecting the company to grow into a $100 billion company.