Apparently, something is wrong with the contact form, in that somewhere along the line (between it and my PA and me), some email is getting eaten. We don't know how, we don't know why, and most importantly, we don't know how much. We only know this is happening at all because I was able to confirm two instances of "I tried to contact you and it didn't go through." (One was resolved by resending with a different return email address. The other, we're not sure.)
Chris is working on a way to make sure this doesn't happen anymore. For right now, giveaways are going to have to be handled in a two-step authentication process, for which I am sorry: specifically, rather than saying "email me," I'm going to be saying "comment here and then email me immediately, so I can tell you if your email is not received." Inconvenient? Yes. Annoying? Yes. The only way I can continue to do giveaways until this problem is resolved? Sadly, yes.
I am deeply sorry for any inconvenience this has caused, especially if you were someone who didn't get a prize because your email was eaten. (Please do not contact me saying "this happened to me a year ago, give me a book." I will believe you. I just don't have the books, or the postage budget, to do anything about it.)