I had no idea this sort of thing was going on, and yeah, I find it very creepy. I used to spend hours in used book shops in NYC, especially the Strand, and I’m amazed that shops allow this. The shops that do may sell more books on a given day, but if the shelves are looted by scanners, why will real book-loving customers keep coming in?
I make a living buying and selling used books. I browse the racks of thrift stores and library book sales using an electronic bar-code scanner. I push the button, a red laser hops about, and an LCD screen lights up with the resale values. It feels like being God in his own tiny recreational casino; my judgments are sure and simple, and I always win because I have foreknowledge of all bad bets. The software I use tells me the going price, on Amazon Marketplace, of the title I just scanned, along with the all-important sales rank, so I know the book’s prospects immediately. I turn a profit every time.