Jason Brooks points to Chuck Skoda’s ruminations:

How do we reference locations in electronic books? Historically, it’s been easy to throw out a page number, and many people were likely to have the same edition as you or at least one with the same page layout. With digital distribution of books coming into stride, that expectation is completely off the table. So, how can we point someone to a specific reference/passage in a book?

The Bible has had this problem covered centuries, but the process also took centuries to come about. Ideally, there would be some standard for breaking up and addressing content within books. Some obvious choices are chapter:paragraph:word or chapter:paragraph:sentence.

Or how about just search? That to me is far more efficient with ebooks than when I was teaching English Lit to 9th and 12th graders in the early 1990s. Back then, I’d tell everyone to open up their copy of The Iliad and then tell everyone to go to page so-and-so and then look for paragraph 3—no, that’s the third full paragraph, not the third paragraph—and then the second sentence—no, semicolons do not make two sentences… and by that time, ten minutes had gone by. Now, I’d tell them to jump to book 2 and then search for “ravening fire”. Far quicker, far easier (especially if I wrote the search words on the blackboard).

If we had every chapter/paragraph/sentence marked in some way, it would look messy & crowded. It might work in the Bible, but that’s a special case, after all.