Amazon Publishing is continuing to broaden its distribution channels, as the New York-based imprint has formed a partnership with Ingram Content Group that will make the company's e-books available to competitors such as Apple, Barnes & Noble and Kobo. As you may be aware, there's some uneasy tension between the rivals, as Barnes & Noble has previously removed Amazon's print editions from its retail shelves in response to the company's former e-book exclusivity in th