One of the world’s biggest advertising agencies has urged marketers to learn from consumer-created content on websites such as YouTube.com, which now has greater reach among some US audiences than MTV, the music broadcaster.

The Leo Burnett agency, whose clients include McDonald’s, General Motors, Heinz and Samsung, said commercials would work on YouTube, which publishes video clips and has greater US reach than MTV, according to Carat, a leading media buying group.

But successful future campaigns would need to imitate viral content - so-called because of its rapid spread online - by being easy to consume repeatedly and to forward on, said Mark Tutssel, worldwide chief creative officer at Leo Burnett.

Advertisers would also have to invite consumer interaction, by allowing people to create their own commercials and comment, even negatively, on brands, Mr Tutssel said.

Speaking at the Cannes Lions International Advertising Festival, he said: “Marketers must learn to let go of the control they think they have over their brand.... Once consumers have interacted with brands they will not go back to being shouted at by marketers.”

The speech, a joint presentation with Contagious, an industry magazine, came as the festival, the leading awards for the $400bn a year advertising industry, awarded a Grand Prix to a campaign designed to look like a homemade internet video.

The advertisement appears to show Mark Ecko, a graffiti artist, defacing Air Force One, the US president’s jet. It claims to have reached 135m people via the internet and subsequent free press coverage.

All week at Cannes, advertising and media executives have grappled with the implications of virals which have reached millions of people via the internet, often by-passing traditional media. A few have involved no spend on media, offline or online.

Industry executives are also worried that the fastest growing part of internet advertising, namely paid-for search, could turn brands into commodities.

But arguing that digital media can tap consumer enthusiasm for brands the Leo Burnett presentation, dubbed Wildfire, cited examples including the Chevy-Tahoe car brand which invited consumer to create their own web commercials. This attracted 5.5m people to a website and produced 22,000 entries, of which only 16 per cent were negative. A VW Golf advertisment shown on YouTube.com also drew 1.9m people.

In an FT interview, Paul Kemp-Robertson, editor-in-chief of Contagious, said: “On sites like YouTube, advertising can be an acceptable part of the landscape, sitting alongside music or films. People may not be interested in advertising but they are interested in brands.

Provided you offer them something entertaining and useful, allow them to interact and reward themfor their interest, they will accept you.” Other successful “virals” have included a clip created for the John West fish brand. This was voted the most popular US commercial even though it has not aired on US television. True to their interactive ambitions, the presentation speakers asked delegates to keep their phones on during the talk and to text their views, which will be published online.

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June 20: Cannes Lions Diary 2: Search under scrutiny

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