Kindle’s "Real" Page Numbers - How They Did It

Per Amazon:

... With our massive selection and knowledge of print books, we were excited to be in a position to help solve this problem. We had to invent an entirely new way to match the streams of text in a print book to the streams of text in a Kindle book, and assign page numbers in Kindle books. There are hundreds of thousands of Kindle books (and growing every day), so to handle a job of this size, we turned to our Amazon Web Services computing fabric. We created algorithms to match the text of print books to Kindle books and organized all of this in the cloud, using our own AWS platform. The results of this work are stored in Amazon’s Simple Storage Service, where we track the complete history of every page matching file we’ve produced. We even found a way to deliver page numbers to books that customers had already purchased – without altering those books in any way, so customers’ highlights, notes, and reading location are preserved exactly as they were.

Some other e-bookstores have added virtual “page numbers” to e-books, but we’ve found that these approaches can be confusing and often inconsistent – they don’t map to the page numbers in physical books, and in some cases they don’t account for title pages, blank pages, and other nuances that we see in print books. We’ve already received a lot of great feedback from customers who like our approach. Real page numbers are already available in tens of thousands of our most popular Kindle books, including the top 100 bestselling books in the Kindle Store that have matching print editions, and we’re adding page numbers in more Kindle books every day. We want you to lose yourself in the reading, so page numbers are only displayed when you push the menu button. ...