On the other hand, centralized circulation data is an incredibly valuable tool for determining the shape and direction for the collection. This is why some univ

On the other hand, centralized circulation data is an incredibly valuable tool for determining the shape and direction for the collection. This is why some university libraries explicitly do not want you reshelving books, even correctly - they want the record that someone looked at it. The bottom x% of books by frequency of circulation can be culled to make way for new purchases. Of course, it is not necessary that the record of usage be in any way related to the patron's identity, but a permanent record of the fact that a patron pulled the book is essential.