The Advertising Standards Authority (ASA) has upheld Telegraph.co.uk's claim to be "the UK's most visited newspaper website", following a formal challenge to the boast.

Editor Will Lewis and online editorial director Edward Roussel sparked criticism from rivals Guardian Unlimited and Times Online in November when they cited Hitwise data giving Telegraph.co.uk the highest number of "visits" amongst UK titles.

Controversy flared because different metrics are used to measure website popularity. The Guardian's site was widely considered the UK's most popular newspaper destination, with a separate ComScore metric reporting 2.93 million "unique users" against Telegraph.co.uk's 1.22 million. Times Online protested it was a third-place site, behind The Guardian but ahead of The Telegraph, all of which trail BBC News.

While the Guardian's favoured "unique users" metric counts only individual readers, the "visits" data, which referred to traffic between July and September 2006, may include multiple visits from the same reader. Telegraph.co.uk had commissioned a high-profile poster marketing campaign that claimed lead status and riled rivals enough to attract a single complaint to the ASA.

But the advertising watchdog today rejected the complaint, saying in an adjudication: "We concluded that, because the ad made clear the 'No. 1' claim was based on the number of visits to the site and also made clear the source of the data and the period from which the data was taken, the claim was unlikely to mislead."

Edward Roussel, Telegraph Media Group digital editor said: "This latest commendation from Hitwise reflects the high degree of loyalty among our UK readers. They are visiting us time and time again for Telegraph.co.uk's quality news, sport, business, arts and opinion, and the volume of their return visits shows there is clearly a market for Telegraph world-class writing and commentary."

Analytics agencies reporting unique users and page impressions put Telegraph.co.uk behind its vociferous critics. The dueling continued last week when the Telegraph's Will Lewis refused to accept questioning from Guardian Unlimited editor-in-chief Emily Bell during a terse public exchange at the 6th Ifra Newsroom Summit in Paris.

The ASA told Journalism.co.uk the complaint came from a member of the public and not from any rival publisher in a corporate capacity, however.

Seeking to unify metrics newspaper sites provide to advertisers, ABCe recently announced it would publish its monthly package of results for newspaper websites on the same day every month, with the first such release due tomorrow.

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