YouTube will introduce advertising into video clips today for the first time as the world’s most popular video- sharing website tries to justify its $1.65 billion (£832 million) purchase price.

The Google-owned site also hopes to reinvent video advertising on the web. YouTube believes that its approach is as unobtrusive as the classifed adverts placed by its search-engine owner. Twenty seconds after a clip begins, a transparent advert appears in the bottom fifth of the video for a further 15 seconds. Clicking on the image overlay plays the advert, but if ignored it simply disappears.

Eileen Naughton, YouTube’s director for media platforms, said: “We are trying to be respectful of the YouTube community, whilst working with marketing partners.” She cited statistics that “less than 10 per cent of users choose to close the image overlay as soon as it appears” as evidence that it does not bother people watching clips.

The model was chosen in preference to traditional forms of television advertising, in which programme-watching is interrupted by a commercial break. Testing by YouTube showed that the approach did not find favour with internet users.

Shashi Seth, group product manager, said: “Our experiments with preroll advertising [a short advert placed at the beginning of a clip] showed a very high abandonment rate.”

Not all videos are eligible for advertising at this stage. YouTube has chosen to work with established media partners, such as Warner Music, in the first wave. Twenty advertisers, including BMW, the car group, and MGM, the film studio, have tested the service.

YouTube is charging about $20 per 1,000 views, with the revenue split between the website and the provider of the content. The scheme will be available only in the United States at first, but an international deployment, including in Britain, is expected within months.

The website is keen to manage who can accept advertising to ensure that household-name brands do not find themselves appearing as an overlay to pornographic, violent or other controversial content. This month Facebook, the social networking site, became embroiled in a dispute after its technology allowed well-known brands to appear on a page produced by the British National Party.

Only YouTube’s 1,000 content “partners”, including the BBC’s commercial unit and Chelsea Football Club, will take commercials initially. A few of those content partners include ordinary people who have become some of YouTube’s most popular providers of clips, such as the British pensioner who goes under the name Geriatric1927. His “channel” has been viewed about 1.95 million times.

Google rapidly developed from a successful search engine into one of the largest sites for classified advertising on the internet and is eating into newspaper revenues in America. Google’s acquisition of YouTube last year, at a multiple estimated at 100 times its then revenues, was seen as an attempt to augment its $15 billion-plus annualised turnover with advertising linked to video clips.

If the approach takes off, it is likely to be adopted elsewhere and become the default form of advertising in video. YouTube, founded in 2005, has rapidly become the dominant video-sharing website worldwide.

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