I don't mind the idea of toys coming to life - happens in toy story after all - and I think make believe / magic / fantasy can be good for kids in terms of development / creativity, but I think the elf on the shelf is a bit freaky looking (the official one I mean) and it's not something I'm planning on getting into. I like the idea of opening a present on Christmas Eve and its special Christmas PJs that they wear that night and wake up in on Christmas morning.