In my experience: Amazon automatically discounts some books, a certain time after their release. I've published several through their subsidiary CreateSpace, and the two that sold more than negligible amounts were discount the same ~28%. One eventually went back to my 'retail' and the other stayed discounted.<p>Again in my experience, Amazon's discounts do <i>not</i> effect the author's take. At least in CreateSpace, the author's royalty is based on the retail price the author sets.