Digital textbook reader startup Kno plans to release its collection to Facebook, allowing its campus customers to buy and read e-books through a social networking service. Simultaneously, the company is running a Facebook contest in which students can earn discounts on e-books. Kno has also announced an updated version of its tablet e-reader application and a Web-based version of the reader. With the new Facebook option, students can study alone or with friends online and can post questions from their e-text to their Facebook news feed.