An email Amazon sent to KDP authors today:
We’re excited to announce that you can now make your new books available for pre-order in Kindle Stores worldwide. With a few quick and easy steps you can create a pre-order page up to 90 days in advance of your book’s release date–your pre-order product page will be created within 24 hours. When you make your book available for pre-order, customers can order the book anytime leading up to the release date you set. We will deliver it to them on that date.
One advantage of using pre-order is that you can start promoting your Kindle book pre-order page on Author Central, Goodreads, your personal website, and other places ahead of its release to help build excitement for your book. Also, pre-orders will contribute toward sales rank and other Kindle Store merchandising ahead of release, which can help more readers discover your book.
Visit your KDP Bookshelf to set up your new book for pre-order.
The Kindle Direct Publishing Team
Questions? Learn more about pre-order on our Help page.