On the other hand, independent open textbook authoring and publishing models are developing. Most notably, the startup publisher Flat World Knowledge already has dozens of college-level open textbooks that are used by more than 900 institutions in 44 countries. Their business model was to offer the open textbook free online, and then sell ancillary products that students are likely to buy if prices are reasonable - print copies, study guides, ePub, .Mobi (Kindle), PDF download, etc. Flat World Knowledge compensates its authors with royalties on these sales. With the generated revenue Flat World Knowledge funded high-quality publishing activities with a goal of making the Flat World financial model sustainable. However, in January, 2013 Flat World Knowledge announced their financial model could no longer sustain their free-to-read options for students. Flat World Knowledge intends to have open textbooks available for the 125 highest-enrolled courses on college campuses within the next few years.