The good news is that my most serious concern is, to a large degree, inside baseball.
My most serious concern is that I can't quite bring myself to believe that a VC-backed company, founded by the creator of a classmates.com style company actually cares about privacy in any meaningful way. My perception of your values erodes any potential trust; it feels like a gimmick to get innovators and early adopters to use it. This also destroys your most obvious value proposition.
My weaker concerns are centered more around design (a lot of awkward and modestly confusing pieces that others have identified), and results that were never noticeably better than Google for me, but were sometimes noticeably worse.
I really hope you take my stated concerns in the right spirit. I know it's not nice to have some stranger you've never met say he doesn't trust you because of his perception of your past work, and his concerns about likely business models. That's why I waited until after the holiday to respond, so at least there wouldn't be tons of people reading the thread when I said it.
