I do this a lot, not just in book stores either. For me, it's the reviews. I see a book (or product) that looks interesting, make a note of it and check the re

I do this a lot, not just in book stores either. For me, it's the reviews. I see a book (or product) that looks interesting, make a note of it and check the reviews online (typically Amazon) to see if it's worth the purchase. If the reviews are favorable and I decide I want to buy it, the choice is pretty simple; I'm already at the online store, the price is usually lower and the purchase is a click away (versus a drive back to the store and potentially waiting in line). If I do bother to check the reviews on my phone while I'm in the store, then it's a simple price comparison, and the online retailer almost always wins again.