Analysts have predicted online video adverts will make $120m in total revenue this year for America's four main broadcast television networks in dispute with the Writers' Guild Of America.

The striking Hollywood writers' main bugbear is they do not get paid extra for shows streamed on the internet. They want a new contract to take it into account.

Tracey Scheppach, senior vice president and video innovation director at Starcom, a major media buying agency, admitted it appeared the networks were making large amounts from internet video.

She told the Financial Times: "Based on what we’re paying for spots across the four networks, we estimate this market to be worth more than $120m."

Scheppach explained advertisers were willing to pay well on the internet as response is better: ""You get 85 per cent recall [with web streaming] versus single-digit recall for TV."

Meanwhile, Accustream, the digital media research company, estimates the entire internet video advert market at $1.3 billion this year.

Its research director Paul Palumbo predicted ABC, CBS, NBC and Fox's share of that would rise because they have the strongest and most popular programmes: "In an expanding universe of content, advertisers cluster around premium inventory."