Britain's Interactive Advertising Bureau is under fire for failing to release certain data in its annual online adspend survey.

A report in UK trade publication MediaWeek claims the IAB/PricewaterhouseCoopers study of 2002 web advertising did not include figures showing that over 80% of spend goes to the ten biggest online media operators, even though the information was available.

Past IAB/PwC reports have included such figures, which detail the proportion of web ad outlay that goes to the top ten online media sales points (both website owners and sales houses). In 2001, 83% of spend went on the leading ten, in 2000 it was 89%, while in 1999 it was 90%.

When the report was released earlier this year [WAMN: 17-Apr-03], IAB chief executive Danny Meadows-Klue claimed the data for the top ten were no longer collated, since the statistic "confused marketers".

However, research insiders have reportedly disclosed that the information does exist, and that 83% of web spend went on the top ten operators in 2002.

As a result, several media agencies are calling on the IAB to release the data, even though many believe the statistic itself is of little significance.

Carat Interactive head Rob Horler dismissed the idea that the big players were getting an unfair amount of spend. "The concept that we miss a whole chunk of opportunities out there is ludicrous. The route for us to cover specialist interest sites has always been sales houses," he declared. However, Horler supports calls for the data to be disclosed. "[The IAB] should be debating what it means for the industry."

One anonymous IAB board member insisted that the figure is not important: "As the whole online industry is growing, the market share of the top ten is not really an issue."

The IAB/PwC report found that online spend rose 18.7% last year to £196.7 million ($328.2m; €280.9m).

Data sourced from: Media Week (UK); additional content by WARC staff