On August 15, Danielle A. Singer and her company Project Therapy, LLC (dba Therapy Threads) filed a class-action complaint against Facebook, Inc. over its claims concerning ad audiences. According to the Complaint, Facebook overstates its audience metrics in order to induce advertisers to spend money on ads on the platform.

The plaintiffs allege, in part, that Facebook’s statements regarding the “Potential Reach” of ads placed on the platform are so inflated that they contradict census data. For instance, the Complaint points to Facebook’s claims about its Potential Reach in Chicago, IL. Facebook allegedly stated that its ads could possibly reach 1.9 million people from ages 18-34 in Chicago. However, the plaintiffs presented census data that only about 800,000 residents of Chicago fell in that age range.

The plaintiffs seek monetary damages as well as an order which requires Facebook to hire auditors and to fix problems identified by the auditors.

While Facebook has not yet responded to the statements made in the Compliant, in 2017, the company stated that it bases its audience reach estimates on several factors and that the estimates are not intended to match the population set forth in census estimates.

Takeaway: When buying ads based on projected audience reach, advertisers should determine what the ad platform factors into such reach estimates and understand that estimates are, of course, never a guarantee.