BING's inventory is made up almost exclusively of art books, but we're interested in purchasing quality books within many subject matters. As for the art books, we're especially interested in things that are very specific in terms of subject matter. We're more likely to want books that deal with one artist or a concise time period. We're also interested in weird and unique items, such as exhibition catalogs and handmade books from small presses. We're less likely to be interested in coffee table books from popular presses or general overviews of art history, including textbooks.
As for other subjects, we'll at least be eager to look at virtually any collection that appears to have a fairly high percentage of quality books. That term is difficult to define, but I'm generally speaking of books that retain some cultural, historic, and monetary value in the years following publication. We're particularly interested in books dealing with African-American history and the black struggle. Generally, things like textbooks and bestsellers have a short shelf life in terms of their cultural and monetary value, so they don't get much traction on the second-hand market.
If you have books that you think we might be interested in, send an email to firstname.lastname@example.org and we can discuss if, how, and when we can take a look at them.