• by Wendy Davis  @wendyndavis, December 30, 2014

Pay-per-click marketers can't proceed with a class-action lawsuit alleging that Facebook charged them for invalid clicks, a federal appellate court has ruled. “The district court did not abuse its discretion in determining that class certification was inappropriate,” a three-judge panel of the 9th Circuit Court of Appeals wrote in a ruling issued late last week. The marketers -- Fox Test Prep and Steven Price, who operates the car site DriveDownPrices.com -- argued that Facebook violated its contract with pay-per-click marketers by charging them for “invalid” clicks.

U.S. District Court Judge Phyllis Hamilton in the Northern District of California ruled in 2012 that the companies couldn't bring the lawsuit as a class-action. She said at the time that the marketers hadn't shown that there was a uniform method for determining which clicks were invalid. Hamilton's ruling allows the pay-per-click marketers to proceed against Facebook individually, but doing so is often prohibitively expensive.

The 9th Circuit affirmed Hamilton's decision, writing that the pay-per-click marketers hadn't shown a “workable class-wide methodology to determine what constitutes a "valid click."

The appellate judges wrote that an expert retained by the marketers failed to offer a method for determining a click's legitimacy.

The expert "noted that the IAB (Interactive Advertising Bureau) Click Measurement Guidelines make clear that it is generally understood in the industry that a click is defined as a request by a human with an intent to view the content,” the appellate judges wrote. "Nowhere in his report or deposition, however, did he provide the actual method for distinguishing between valid and invalid clicks."

The appeals court added that the marketers' expert said he "knows of no sources, including the IAB guidelines, that provide specific parameters for determining what constitutes a valid click."

The legal battle dates to 2009, when Price, Fox Test and other pay-per-click marketers sued the social networking service for allegedly charging them for invalid clicks. The marketers sued shortly after tech news site TechCrunch reported on an influx of complaints about perceived click fraud on Facebook.

U.S. District Court Judge Jeremy Fogel in San Jose, Calif. ruled earlier in the proceedings that Facebook's contract with marketers disclaimed liability for clicks that were "fraudulent," in the sense that the clicker had dubious intentions. But Fogel ruled that the disclaimer didn't apply to clicks that were "invalid" -- such as when technical problems prevented users from reaching a landing page.