siljalineI'm lovin' that double widePremiumReviews:
Facebook "graph search" is sponsored by Bing within Facebook.
As cited in some of the links in this thread, Facebook wants the user to search the Net from their Facebook accounts.
While the tool is useful to the extent that you can find "stuff" that was shared publicly or otherwise that you were possibly not aware of at the time that one could redact from that user's "timeline".
Most that I know or just only now getting a handle on what it really does.
That said, Facebook wants more of Google's search market other than use of it within Facebook accounts.