The recent $90 million settlement of a click fraud suit against Google - considered a favorable outcome for Google - hasn't dampened the motivations of those seeking redress for what they believe is a pervasive problem. A recently established website, ClickFraud Legal Center, urges those who believe they have been victims of click fraud to submit relevant information to the site in preparation for another class action suit.

"We have a consortium of law firms from around the country ready to recover your money. If you have paid for click advertising, studies show that anywhere from 20-40% of that cost was fraudulent," according to the site.

According to Michael Caruso, cofounder and president of ClickFacts, an internet advertising auditing firm, "Another lawsuit in the works just validates our findings that the fraud is at much higher rate than Google and other networks would like to admit."

"If advertisers and attorneys saw fraud under 10 percent, it would be dismissed as an accounting error, but the lawsuit and our client data makes it clear, that the fraud rate is much higher than that," Caruso adds.