Twitter has been the Internet success story of the past year. Founded in 2006, the micro-blogging service sends 3 million messages per day and has been adopted by every technologically-aware celebrity. Even Twitter’s highly-publicised technical problems, the downtime, hacking attempts, and news of a celebrity-snooping TV show has not put people off (although only 40% of accounts remain active a month after signing up).

As a start-up, Twitter raised $55 million of venture capital and now has an estimated value somewhere in the region of half a billion dollars. Even your own Twitter account could be worth something: according to TweetValue.com, sitepointdotcom is worth $10,991 and Stephen Fry is $42,542. Even my own paltry effort is worth $25 (all bids considered!).

It’s not bad for a company that is yet to earn a penny. So why is Twitter worth so much, especially during an economic downturn?

More: http://www.sitepoint.com/blogs/2009/06/26/will-twitter-start-charging/