Yahoo: comScore Underreported Our U.S. Page Views By 1 Billion Last June

Yahoo just put out a press release calling out comScore for seriously underreporting the site’s U.S. page views and duration metrics in its June report.

Yahoo says an error skewed the numbers in the June 2010 publication pretty badly – the company claims comScore underreported its U.S. page views by more than one billion and its duration metrics by more than 850 million minutes.

Based on the corrected numbers, on a month-over-month basis, Yahoo!’s U.S. page views were down 4.7 percent versus the reported 7.4 percent, Yahoo says.

For the record: comScore hasn’t given any statements regarding the alleged error yet, but Yahoo says the measurement company is committed to issuing the correct numbers in the company’s next data release. The Internet company adds that it saw itself forced to make the statement today due the sheer size of the error.

I like how the press release is titled to make it seem comScore is actually the one stepping forward with a statement: “comScore Reports Error in Yahoo! June Page View and Duration Metrics”. It’s the details.

Chief exec Carol Bartz also had some passive-agressive words for the company to spare:

“We believe comScore is committed to addressing the error and ensuring accurate and reliable reporting of marketplace performance. Yahoo! is fully prepared to work collaboratively with comScore to develop policies and practices to ensure the timely correction of inaccurate information,” added Bartz.

Update: comScore EVP Linda Boland Abraham has now commented on Yahoo’s press release via the company blog:

Last week we notified Yahoo! of a processing error confined to data specific to Yahoo! which resulted in under-reporting Yahoo! Page Views and duration metrics by 2 to 3%. This morning, Yahoo! made an announcement about the revised data.

The Yahoo! case is a regrettable error which was the result of processing specific to Yahoo! As such, it was an isolated, one-time error that did not affect any other client’s data. In addition, no panel data metrics were affected, including data reported on Yahoo!. After a thorough review, we have identified a process to prevent similar occurrences in the future.