You never know what you might find in there. I've found some interesting poetry compendiums along with everything from Harlequin novels to atlases.
They're a great way to promote reading and each box is a great reflection of the person maintaining it.
I love the one we have! They are such fun and wherever we go on the next move, we are sure to keep putting them up and passing them on as we go.
I hope it encourages people to read more and read more to their kids. I agree with you! There are some amazing finds in there. Once a month, I put in something that has just been printed, so it is a fun find for others. It is funny since I have been doing that, others have reciprocated with the new titles that they just purchased and read.
I love their spirit!