Some people I know leave their Facebook profiles fairly blank to try to avoid targeted advertising. Facebook engineers have found a way around this with what they call “inferential targeting” – and they’ve filed a patent application to cover their method, as first noted by Inside Facebook.
The idea is that you can infer someone’s interests from their browsing patterns and in some cases, the interests of their friends.
The patent application acknowledges the original problem, which includes not only deliberate omission as I mentioned above but also general incompleteness. “Members of social networks often do not populate their profiles to include all of their interests and other personal information, the patent summary says. “As a result, using personal information in ad targeting is typically not available for all members of the social network. Traditional ad targeting techniques are thus limited because they can reach only a subset of the members in the social network for whom the ads are intended.”
The summary describes Facebook’s invention as making inferences from the interests of direct connections (friends) and also indirect connections (friends of friends). One example given in the patent application is that a user might respond to an ad targeting a certain college if a large number of their friends went to that college. The application also suggests that inferential targeting could be used to measure the depth of someone’s interest.
“For example, … an advertiser may require that the member list the interest in surfing and be connected to five other members who also list an interest in surfing for the targeting criteria to be satisfied. Thus, the advertiser is able to target members with a more “extreme” interest using inferential ad targeting techniques.”
Facebook’s user base now over 500 million and it’s likely that the average user has amassed a critical mass of friends on the network. As a result, Facebook has the data for increasingly sophisticated algorithms to target its ads. For users who are uneasy about ad targeting, there is increasingly little they can do about it, aside from deleting or abandoning their accounts.