• by Wendy Davis  @wendyndavis, December 28, 2010

In the latest twist in a long-running potential class-action lawsuit about Google's parked domain program, a federal judge has ordered the search company to reveal potentially confidential information about four AdWords advertisers who also are clients of the Internet marketing firm Wpromote.

The ruling, issued earlier this month by U.S. Magistrate Judge Howard Lloyd in the Northern District of California, stems from several lawsuits filed in 2008 complaining about Google's AdSense for Domains and AdSense for Errors programs, which place ads on sites that have little or no editorial content. Users often land on such sites after mistyping a URL.

The lawsuits, now proceeding as one consolidated action, originally alleged that these sites are low-quality and yield worse conversion rates for marketers than ads that appear on Google's search results. In an amended complaint filed last month, the marketers say they believed that clicks on ads on parked domains "were unlikely to lead to desirable business outcomes, and that placement on such pages could damage their brands."

Google, which says that parked-domain ads "perform as well as or better than ads on Search and Display Network sites," recently filed papers seeking dismissal of the case. The company argues that it didn't mislead or harm any of the plaintiffs by placing their ads on parked domains or error sites.

Separately, as part of its defense, Google tapped Wpromote CEO Michael Mothner to prepare a report arguing that the lawsuit should not be granted class-action status. That's a key issue for Google because even if the case isn't dismissed by the court, individual marketers' damages in click-fraud lawsuits tend to be too small to make it worthwhile for them, or their attorneys, to pursue the cases individually.

Mothner wrote that the lawsuit should not proceed as a class-action because conversion rates vary depending on the advertiser. In particular, he said that some ads have "higher conversion rates on parked domain and error page websites than on other websites," according to the court's ruling.

To arrive at his conclusion, Mothner examined aggregate data from four search marketers that his firm represents. That move, however, appears to have paved the way for the marketers who are suing to learn the identities of Mothner's clients -- despite Google's allegation that its contract with those marketers includes confidentiality provisions.

"It was Google (or Mothner) who put the Wpromote clients' identities at issue in the first place, so it cannot use confidentiality provisions to shield itself from disclosing their identities now," Lloyd wrote. He gave Google until Dec. 22 to comply.

Google has not yet responded to a request from Online Media Daily for comment. But it appears from court papers that the company has not yet disclosed the information; instead, Google appears to have asked Lloyd to modify his order.

Late last week, the plaintiffs filed papers alleging that Google "is in violation of a court order" because it had not yet turned over information about the search marketers.