The US television industry faces a $2bn slump in advertising revenues during the next four years as advertisers turn away from broadcast and cable networks, according to a new report.

Digital video recorders that allow viewers to skip through commercials have knocked confidence in broadcast and cable advertising while younger, tech-savvy audiences are deserting their TV sets to spend more time online.

The Global Media Intelligence report by Screen Digest, the media research company, says some of the decline will be clawed back by US TV networks by online video advertising, which it expects to triple during the next four years.

But with online video advertising representing only 2.2 per cent of all TV advertising, this will not be enough to offset the slump, exacerbated by the recession.

Screen Digest forecasts US broadcast and cable advertising revenues will fall from $69bn in 2008 to $67bn by 2013.

"We're at an inflection point in the TV business model," Arash Amel, one of the report's authors, told the Financial Times. "Online video is not mature enough and won't mature quickly enough to fill the gap left by the decline of traditional TV advertising."

However, he said online video advertising was growing "exponentially" - with the big four US networks dominating the nascent market at the expense of sites such as YouTube.

"Sites marketed and sites directly supported by the [important] content owners have gained a [substantial] lead over third-party sites like YouTube and Joost," he wrote in the report.

Online video has boomed in the three years since ABC became the first network to start streaming full episodes of its shows online. Since then, every other network has followed suit, with CBS, NBC and Fox each promoting its web service to its TV audience.

In the UK, the BBC has quickly built an online audience with its iPlayer. ITV and Five have also put programming online.

In the US, News Corporation and NBC Universal own Hulu, a free streaming service that operates as an online hub for their TV content. The site is only available in the US, but there are plans to launch it worldwide.

Walt Disney, which owns ABC, recently joined Hulu as an equity partner.

The success of Hulu and the sites operated by ABC, CBS, NBC and Fox has given the big US networks a dominant position in online video advertising.

They account for more than half of the $448m ad-supported online TV market in the US in 2008. Screen Digest expects the market to be worth $1.45bn by 2013.

In making their content available for free online, Mr Amel said the networks had ensured they would avoid the fate of the music industry, which failed to respond to the threat posed by the internet.

Younger viewers are watching more TV online and using services such as Hulu, with many ditching their cable subscriptions in favour of internet viewing.

The next challenge for the networks is to capitalise on this shift, according to Mr Amel, by running more ads per show.

Programmes streamed on the web typically contain five or six commercials per hour - compared with more than 20 that run in each hour of broadcast TV.

"There's no reason why online video won't make up the shortfall [in TV advertising] within five years," said Mr Amel.

"But the question is how aggressive the networks in the US and the rest of the world are prepared to be."

By Matthew Garrahan in Los Angeles

Published: June 29 2009 03:00