Surely that's only true for a vanishingly small subset of fields of interest? I mean come on, Amazon didn't invent obscure topics. Bookstore people would know

Surely that's only true for a vanishingly small subset of fields of interest? I mean come on, Amazon didn't invent obscure topics. Bookstore people would know more specialized stores, though this was naturally less true at chain stores. This was at least as effective as Amazon giving you a list of other books bought by people who bought the one you're looking at.