I don't actually think of books so much as I think of browsing stores for actual goods. On the one hand, I have too much stuff (http://www.paulgraham.com/stuff.html) on the other hand, I'm far more likely to unexpectedly encounter a useful and actually buy a thing (say a cooking tool) at the mall than online (even something simple, like a quality spatula).

I wouldn't even look at cooking items online. No AI recommendation engines have ever recommended cooking utensils to me that I can remember, and certainly nothing that I was interested in. I've never made a conscious decision to outfit my kitchen, so I've never gone on an online shopping spree for that sort of thing. However, if I walk by Williams-Sonoma in the mall, I may stop in and check out what they've got.