Facebook’s advertising platform was not built to help social media users understand who was targeting them with messages, or why. It is an extremely powerful system, which lets advertisers target specific users according to a detailed range of attributes. For example, in 2017, there were 3,100 people in Facebook’s database who lived in Idaho, were in long-distance relationships and were thinking about buying a minivan.
That ability to microtarget specific messages at very particular groups of people can, however, let dishonest advertisers discriminate against minority groups or spread politically divisive misinformation.
But as Congress continues to review ideas, it’s not yet clear how best to make these systems more transparent. It’s not even obvious what information people most need to know about how they are targeted with ads. I am part of a team of researchers investigating where risks come from in social media advertising platforms, and what transparency practices would reduce them.
Analyzing Facebook ads
In response to users’ and regulators’ concerns, Facebook recently introduced a “Why am I seeing this ad?” button that is supposed to provide users with an explanation for why they had been targeted with a particular ad.
However, the only people who see Facebook ads are those that Facebook’s algorithms choose, based on advertisers’ chosen criteria. Without help from Facebook, the only way to audit advertisers and the ads they buy is to directly collect from actual users the ads they see in their timelines. To do this, my research group developed a free browser extension called AdAnalyst that users can install to anonymously collect data about the ads they see.
More than 600 people shared their data with us, which allowed us to observe more than 50,000 advertisers and 235,000 ads from March 2017 to August 2018. We learned quite a bit about who advertises on Facebook, how they target their messages and how much information users can get about why they’re actually being shown specific ads.
Oana Goga screenshot from Facebook.com, CC BY-ND
Who are Facebook’s advertisers?
Any Facebook user can become an advertiser in a matter of minutes and just five clicks. The company does not seek to verify a person’s identity, nor any involvement of a legitimate, registered business.
Our AdAnalyst data revealed that just 36% of advertisers bother to get themselves verified. There is no way to truly identify the remaining 64%, so they can’t really be held accountable for what their ads might say.
We also found that more than 10% of advertisers are news organizations, politicians, universities, and legal and financial firms, trying to promote nonmaterial services or spread particular messages. Efforts to determine if any of them are dishonest, spreading disinformation or racially targeting messages is much more difficult than, for instance, figuring out whether someone has falsely advertised a bicycle for sale.
Very specific targeting
We found that the most-targeted user interests were broad categories like “travel” and “food and drinks.” But a surprising amount of ads, 39%, were more specifically directed using keywords advertisers entered, for which Facebook suggested related interests and categories. For instance, an advertiser could type in “alcoholic” and get suggestions including “alcoholic beverages” – but also people interested in “Alcoholics Anonymous,” and users whom Facebook’s algorithms had identified as being part of a group called “adult children of alcoholics.”
Screenshot of Facebook.com, CC BY-ND
In addition, we observed that 20% of advertisers use potentially invasive or opaque strategies to determine who sees their ads. For instance, 2% of advertisers targeted ads at specific users based on their personally identifying information, like email addresses or phone numbers, which they had collected elsewhere, perhaps from customer loyalty programs or online mailing lists.