Originally Posted by RHWright
I was going to cite automobiles/gas as an example, but I think the case of someone like Sony is somewhat more apropos. A Sony CD player doesn't just play Sony music. It plays just about any CD from any label. (Never used a Sony ereader, so I don't know how much they carry that model into that arena.)
Sony started out with a proprietary format for their ereaders in the early days, but several years ago, they switched to the industry standard Adobe Digital Editions EPUB. B&N supports ADE EPUB, but uses their own proprietary DRM for books purchased from them (although my understanding is that they are working with Adobe to include their DRM in the standard). My understanding is that Sony has one of the best ADE implementations out there.