I have a signed copy of a collector's guide that is basically a sticker. It's not like this person is famous or anything.
The only thing I could thing of is that it was written by two people and rather than pay for one of the author's to show up and sign a stack of books or send the pile of books to one house and then another; they just handled it with stickers.
Not that I paid any premium for it but I thought it was a bit tasteless.
"The farther we go, the more the ultimate explanation recedes from us, and all we have left is faith."