AdWords advertisers have won the ability to sue Google over ads placed on error pages as the U.S. Court of Appeals in San Francisco disagreed with a prior ruling from a lower court judge, which rejected their request for class action status.

According to the advertisers, the search giant billed them for ads that appeared on error pages and parked domains between July 2994 and March 2008. Bloomberg Business reports:

Monday’s appeals court ruling returns the case to a trial judge for further consideration. The appellate panel also sided with the advertisers related to a method for determining damages in the case…U.S. District Judge Edward J. Davila in San Jose, California, denied class certification in January 2012, partly because it would be difficult to determine which advertisers had been hurt by the placement of their ads. Davila also found that some clicks on ads on those pages could have resulted in sales for the advertisers, according to Monday’s decision.

Google is not commenting on the matter.

Separately, in somewhat related news, there’s a new study out that reportedly shows that the company has been charging YouTube advertisers even when it thinks ads were viewed by robots. Google has commented on that. Business Insider shares this statement from the company:

We’re contacting the researchers to discuss their findings further. We take invalid traffic very seriously and have invested significantly in the technology and team that keep this out of our systems. The vast majority of invalid traffic is filtered from our systems before advertisers are ever charged.

It will be very interesting to see how both of these narratives progress.

Image via Google