We had been given this book by our children's godmother and for more than a week, this was all the kids would ask for (both of them!). Sometimes Zoë would just come out with the book at odd times during the day and go, "'geon! Read!"
I think they like the fact that they've been "entrusted" with not letting the pigeon drive the bus and that they'd been given the license to say NO a zillion times throughout the book. What I like is that it turns book-reading into an especially fun interactive activity.