An excellent point. An excellent point.

I'm sure that has something to do with it, but they do show you which book you've bought that ostensibly triggers the sugguestion and some of them make good sense - like I picked up Frederick Jackson Turner's The Frontier in American History and promptly started getting recs for the many many books that have taken off of or taken on Turner's Frontier Hypothesis. ...So. I. Don't really know. Alas, alas Amazon! If only you were trying to sell me Burney's sources and respondents!