I have so many copies of The Very Hungry Caterpillar - I have 2 of the board books, one large paperback and this sticker book. I never took the stickers out and put them into the book because... well, because I thought it was more fun to use it as a backup book for when I can't seem to find the others (lost under the bed, left at Grandma's house etc).
But! I have found a use for my Count with The Very Hungry Caterpillar book. Erika has been reluctant to go to the toilet on her own (she always wants me to go with her and wipe her botty, or carry her to put her on the toilet) but she loves to stick the stickers in the book. So I told her each time she does everything herself on the toilet, she gets to stick a sticker in the book.
In fact it's going so well, that I may have to buy another sticker book of some sort for her to do. Though I'm hoping by the time stickers run out, she will be independent and not need me in the bathroom anymore.