They are all remaindered books. I get a big fat zero for each sale. Remainders are a fact of life, esp. when you write adult books, which tend to stay in print for less time than YA or children's. Also, once your book comes out in paperback, the hardcovers are pretty much not going to sell.
Oh well, like Daedalus says, these are all “quality bargain books for the independent reader.”
Want some? Just click here. [Full disclosure: I might just pick up some myself – if the film people who have optioned Learning to Fly ever do make it into a movie, hard covers of the book could be a hot commodity.]