Facebook applies for ad-targeting patent

Earlier this month, Facebook filed for a patent to further hone its ad-targeting technology so that ads can be based on what a user's friends interests may be. The reason for this, it appears, is so that Facebook can better serve ads toward users who have not filled out their profiles with enough information for traditional ad targeting.

Facebook calls this second-degree targeting "inferential."

"Members of social networks often do not populate their profiles to include all of their interests and other personal information," the patent application explains. "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."

Obviously, just because you're friends with someone doesn't mean you share the same interests. But if a sizable percentage of your Facebook friends share the same interests, it's pretty safe to assume that you might, too. The patent application suggests that advertisers may be able to select how heavily they want inferential targeting to be weighted.