I've won quite a few giveaways on LibraryThing, and not too many send out the book right away; some of them take a couple of months, or even longer. There are two or three on LT I've never heard anything more about after winning 'em. LT takes author pokiness into account; I won one from the December batch, and they say "Hang tight. You can mark the book as not received after Mar 3rd."
contact@booklikes.com or also at kate@booklikes.com
So far I had zero problems with giveaways. I won four books in those last months and received all of them within 24 hours.