Once upon a time, when you checked out library books they would stamp the due date on a little sheet of paper glued to the front cover. This was not only a reminder when it had to be back (although that meant no online renewal), but it also showed you how popular or not a book might be.
I once checked a book out of the library at Harvard, and the last time it was checked out, at least according to the due date form, was in the 20's and before that it was last checked out in 1909. That was pretty cool. But the only way I knew that was because of that sheet of paper at the front. Books no longer have that.
I am reading a book right now that I found in the new books section, and I thought "Hey, I could be the first person to be reading this book since it was purchased by the library." And I might still have that idea, except that someone else wrote in the book, (and really unimportant statements as well) and so my image was shattered. But, if there was a due date sheet at the front I would have already known that someone one, or several people, had already read it.
I miss that due back paper.