The new emerging world of e-books has a potential dark side to which few are paying attention. E-books make censorship and other restrictions on the freedom to read possibly easier. In 2009, Justin Gawronski, then a Michigan teenager, was one of many Kindle readers who learned what you think is yours isn’t when it comes to digital texts.

In Bexar County, the new library is devoid of printed books, and patrons seem quite happy. Instead of books packed on shelves, the new BiblioTech library’s collection of 18,000 titles is stored electronically. To read a book, a patron downloads one on his or her e-reader or on one of the 600 or more available for loan. It is the nation’s first all-digital library.

For almost as long as there have been books, readers have underlined passages, dog-eared pages, and scribbled in margins. Historians consulting surviving copies of Books of Hours, devotional works first compiled in the 13th century, run across all kinds of marginalia. One woman even listed the contents of her linen closet.

For years, books have made money for publishers, agents, and even writers. Now it’s only a slight exaggeration to say there remains money only for publishers and a bevy of writing stars. The following very short course in the new economics of book publishing will bear out this claim.

Booktrack, a New Zealand firm, is adding ambient sounds, sound effects, and even music to ebooks. By doing so, it hopes to transform reading the way sound transformed silent film.

One only had to read the first sentence in the “Deluxe Reading Group Edition” ebook of Paula McLain’s novel The Paris Wife, based on the love affair between Ernest Hemingway and his wife Hadley, to come across a striking example of the promise and pitfalls of electronic publishing.

What is happening to books today is as important a moment in history as five centuries ago when a German blacksmith with the unwieldy name of Johannes Gensfleisch zur Laden zum Gutenberg created moveable type and launched the printing revolution. In the years since, technology has made the design, printing, and delivery of books easier, cheaper, and faster.