If you are self-published or an indie author, this is still very possible to do and very much within your best interests. Preorders can provide you the necessary revenue for you to place a significant initial order at your author discount rate.
Example: the retail price is $20.99 plus S&H and in some states tax. Your author rate is $8.40 per book. You could offer a preorder rate of $15.00, which will cover your author rate, plus S&H, etc. and still have change to spare. Preorders are not intended to generate royalties, but rather to buzz about your book and reviews on Amazon to boost book ratings.
Promoting your book weeks or even months prior to its release will build the needed word of mouth buzz. Accepting preorders just makes good sense or cents rather. Once the book does release, most of the promo work should be done. At that point, your book could be riding the wave of a successful pre-release campaign and word of mouth sales could then bring those desired royalty sales for months to follow. Building your book buzz will benefit your signing events and help open doors for media interviews.
To preorder a signed copy of my newest book for only $15.00, which includes shipping and tax, please contact me at firstname.lastname@example.org and request an order form. "Where Two Rivers Meet" is the first in the Washington's Woods series. The sequel, "Where Chains are Broken" is in the works now along with the third book, "Where Love is Spoken."