Geoffrey A. Fowler writes: “You probably think of Amazon as the largest online bookstore. Amazon helped make ebooks popular with the Kindle, now the dominant e-reader. Less well known is that since 2009, Amazon has published books and audiobooks under its own brands including Lake Union, Thomas & Mercer and Audible. Amazon is a beast with many tentacles: It’s got the store, the reading devices and, increasingly, the words that go on them. Librarians have been no match for the beast.”