Oakland, California Facebook, which runs the world's largest social networking website, won a court ruling on Friday rejecting a bid by thousands of advertisers to sue the company as a group for overcharging them.

US district judge Phyllis Hamilton in Oakland, California, denied the advertisers' request for class-action status, saying they failed to show they had enough in common to sue for breach of contract and violating California's unfair competition law.

"The court is persuaded by Facebook's argument that plaintiffs have not shown that they have a viable method for proving each class member's recovery," Hamilton wrote. "The need to determine both liability and damages on an individualised basis makes this case inappropriate for class treatment."

Jonathan Shub, a lawyer for the advertisers, declined to comment. Facebook spokesman Andrew Noyes said the company is reviewing the decision.

Class certification often leads to higher recoveries and allows plaintiffs to cut legal bills.

IPO expectations

Facebook is expected to conduct perhaps the most anticipated US initial public offering ever. The Menlo Park, California-based company is valued at $95.8 billion (Dh351.8 billion), according to SharesPost, which tracks valuations of private companies.

In their 2009 lawsuit, the advertisers accused Facebook of overcharging them on their ‘cost-per-click' contracts, under which they paid fees each time users clicked their ads.

According to the advertisers, Facebook improperly imposed charges for nonexistent clicks, for clicked ads that never opened, for clicks caused by server problems, and for accidental multiple clicks by individual users, among other types of clicks.

Hamilton scheduled a May 17 conference to discuss how best the case should proceed.