I wish I knew about pre-sales. Basically, you can promote your book before it hits the market, and create an aggressive campaign leading up to your sales date. That way the book will hit a higher rank for a category you’re promoting within Amazon, and help your overall sales rank. I choose here to only talk about Amazon because that’s where the bulk of my book sales come from. I’m a firm believer in an 80/20 lifestyle, so I put all of my energy into promoting and selling on Amazon.