[mjrube94]

One of the resonders to my post told me he called customer service to find out exactly what they do. Apparently, they buy these books in order to sell them to mom-and-pop outfits that are not big enough/technical enough to have their own website. It sounds like most of what they look for are requests from these stores, which is why not everything sells. I've also found that things they wouldn't buy the first time I checked, they would buy at some later point, so I've decided to go back every quarter or so and check the ISBNs again. It takes less than an hour, and if something opens up, why not? I've had the most luck with old textbooks.