Facebook graph search. I don't know anyone who likes it. In theory it sounds like a great idea: a Facebook search that helps people discover shared Likes and connections. I can dip into my friends' recommendations to find something that I'll really like, because they like it.
I can see a couple of issues here:
First of all, anxieties over internet privacy. Given the recent revelations surrounding Government online spy programmes such as Prism, it's yet another trust issue and should rightfully raise concerns over online privacy.
It's a very real problem. Remember the 'Actual Facebook Graph Searches' Tumblr? It found results like 'Married people who like Prostitutes' (full article on Mashable).
Fair enough, Facebook did ask me the other day to check my privacy settings because graph search was coming (perhaps to prevent outrage from all those married people who like prostitutes 😉 ). I'd also recommend that you do not display your relationship status (unless you'd like to invite unwanted suitors..).
The second point is more around graph search's usefulness. Facebook is commonly known as a social network - unlike G+ or Twitter which are interest-based. Hence, I go to Twitter for my interests, not Facebook (sorry).
Graph search however assumes that my social contacts and interests overlap. That I'd use my social contacts (e.g. family) to look for and find what I'm interested in. While this could work for fairly generic stuff such as 'best restaurant in Edinburgh', it's hard to see how I could use it for anything more specific - i.e. anything that I'm REALLY interested in. Such as a recommendation for coop games for either PS3 or Xbox 360, that don't involve shooting!
We'll have to wait and see. As with all things social, it's ultimately about the users - and if they won't use Facebook graph search, because it's creepy / pointless / whatever, then it'll fail.