It's physically easier (no tiny books deep back sandwiches between large encyclopedias), similar books or books in a series are often the same kind of size (coo

It's physically easier (no tiny books deep back sandwiches between large encyclopedias), similar books or books in a series are often the same kind of size (cookbooks are larger, paper back novels are smaller), if you know what the book you want looks like it's very easy to narrow down where it is and it's very easy to put things back/together.