Matt Buchanan of the New Yorker Elements blog writes:
Graph Search will eventually index virtually all of the content on Facebook—every link that’s ever been posted, every status update, every piece of data that outside Web sites have shared with Facebook through its Open Graph program—but what users will get starting today is fairly limited in its scope, restricted to searches of photos, people, places, and interests. It doesn’t work on mobile yet, either. And it is ultimately limited by the kind of information that people share on Facebook. But it is already a powerful tool for excavating information that would otherwise go unnoticed, and for spotting previously undiscovered patterns.