Media playback is unsupported on your device

Twitter: How it began and how much it is worth

7 November 2013 Last updated at 01:49 GMT

Newsnight's David Grossman looks at the history of Twitter as the company begins its first day of trading after listing on the New York Stock Exchange.

The giant microblogging site, founded just seven years ago, is worth more than $18bn.

Four young friends started Twitter but over its lifetime those friendships have broken down.

Most watched

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.