In less than a year the site has from a idea about sharing travel videos to one of the biggest names in poular culture.
Time suggests its popularity springs from its timely arrival at the intersection of three 'revolutions'.
First, advances in video production made possible by cheap camcorders and easy-to-use video software. Second, the social revolution that pundits and analysts have dubbed Web 2.0. It's exemplified by sites like MySpace, Wikipedia, Flickr and Digg: hybrids that are useful Web tools but also thriving communities where people create and share information together.
The more people use them, the better they work, and more people use them all the time, a kind of self-stoking mass collaboration that wouldn't have been possible without the Internet.
The third 'revolution' is a cultural one. Consumers are impatient with the mainstream media. The idea of a top-down culture, in which talking heads spoon-feed passive spectators ideas about what's happening in the world, is over.
People want unfiltered video from Iraq, Lebanon and Darfur, not from journalists who visit there but from soldiers who fight there and people who live and die there. µ