Barnes and Noble Used Program
As B&N begins its third party seller program for invited sellers, in what they call "Beta" mode, there are a variety of ways they could elevate this part of the website. One of the issues I would consider most important would be integration of their used books into the metasearch engines, especially Addall and Bookfinder. I would not be surprised if this action alone doubled the site's used book sales. As it is now on Addall, Barnes and Noble only offers their own books, often showing up at the bottom of the page or not at all. This would be a huge boon for online sellers on B&N proper or through Alibris.