It's a big site, and it is certanly possible that i missed a contest somewhere, but I don't see any survey type contests listed in the news feeds in the past few weeks. If you entered such a contest here, then yes, it could very well be legitimate. If you didn't enter any such contest (and just having an account doesn't generally enter you into a contest due to legal requirements and whatnot) then it probably is the worlds oddest phishing attempt. Thats not an e-mail I've seen used before, though it could certanly be a new one. I've asked in our admin section if anyone knows anything about this, if possible hold off for a day or so before you decide what to do. I'd be leaning towards it not being normal though. if you like, forward that e-mail as an attachment to email@example.com and I can take a look at the header info and see if it came from us or not.