In my experience, it's been the source of some serendipitous discoveries. On microfilm or microfiche, you might catch a glimpse of something really interesting

In my experience, it's been the source of some serendipitous discoveries. On microfilm or microfiche, you might catch a glimpse of something really interesting on the nearby pages, which sends you down a completely different track. Just like when you go to a library for one book, then discover two or three really relevant ones on the adjacent shelves. You don't always get that same experience from some machine learning 'Related Books' algorithm.