YouTube has launched a video clip culture

YouTube is the leading net video download site in the US, with 29% of the country's multimedia market, according to traffic monitor Hitwise.

The site specialises in short, home-made, comic videos but a growing number of pirated clips from mainstream broadcasters can be found also.

Last month 2.5 billion videos were watched on YouTube, the company said.

YouTube said that its videos account for 60% of all videos watched online in the US. It has almost 20 million visitors to the site each month, according to Nielsen/NetRatings.

Videos are watched free on the site and the company is still working on developing advertising and other means of generating revenue to support the business.

MySpace, the social networking site popular with teenagers, has close to a 19% share of the market, according to Hitwise.

Yahoo, Microsoft's MSN, Google and AOL each have 3 to 5% of the video search market.