Paper now making Books in most obvious business move ever

Paper making a Book? That would follow logic. But the Paper we're referring to here is actually an iPad sketchbook app and the book?

via Tech News Headlines - Yahoo! News http://www.engadget.com/2013/10/01/paper-now-making-books-in-most-obvious-business-move-ever?ncid=txtlnkusaolp00000589