The most popular online action game franchise, Counter-Strike, achieved 7.6 billion viewer-minutes in the past month, according to the specialist researcher Gameasure.

The finding puts the game — in which online players team up to tackle terrorists in a sprawling virtual world — far ahead of the most-watched broadcast TV show in America last week, the CBS drama NCIS, which notched up an estimated 4.2 billion viewer-minutes over the same period.

Ben Lukawski, managing partner at MindShare, the advertising group, said: “The comparison conveys just how big in-game advertising is going to be. TV is not going to die, but all the data we see tells us that the majority of young people, from six years old up, game.”

While the latest broadcast episode of NCIS drew a one-off total of 17.4 million viewers in the US, Counter-Strike, which has sold about ten million copies, is being played by hundreds of thousands of gamers at any one time — most of them young males.

With the online gaming community exceeding 100 million unique players and growing rapidly, Yankee Group, the consultancy, forecasts that the in-game advertising market will reach $732 million (£370 million) in America by 2010, a 13-fold increase on last year’s figures.

That represents just a fraction of the American TV market — where Procter & Gamble alone spent $3 billion in the first ten months of 2006. But in-game groups are attracting heavy investment and a growing roster of advertisers who pay for display-advertising on in-game billboards and “virtual” product placements.

The format also allows advertisers to tailor campaigns for different regions and to track how many times an advert appears on screen Valve, the developer behind Counter-Strike, signed a deal this week with IGA Worldwide, which will supply advertising into the game. IGA’s advertisers include T-Mobile, Ben Sherman, MTV and Jeep.

In April Microsoft bought the advertising group Massive, which counts Coca-Cola and Honda as clients, in a deal estimated to be worth up to $400 million.

Publishers have for some time incorporated brands in virtual landscapes to make gameplay more realistic. But high-speed internet access and the launch of internet-enabled consoles such as Nintendo’s Wii and the Sony PlayStation 3, allow more interactive campaigns.

Domino’s, the pizza chain, recently paid for an interactive in-game advert that allowed players to order out for food over the internet by shooting pizza box targets.

Marketers can also count on an engrossed audience. Guy Phillipson, the chief executive of the Internet Advertising Bureau, said: “Gamers are a highly engaged, captive audience. They have their noses inches away from the screen. If marketers could ask people to stand in front of a traditional billboard for a couple of seconds, they would. In these games, they don’t have to.”

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