Ever wondered how much Amazon discounts your book or how much used copies are going for? If the price fluctuates — does that affect sales? camelcamelcamel provides simple, free Amazon price drop alerts and price history charts. Here’s an example of a book’s price history. It’s designed for customers to be able to get the best price on an item… but, as the publisher, you can also use it to track your books. The service only tracks products it knows about, so head over and enter the ISBN of your book right now so it’ll be in their tracking database. Did you try camelcamelcamel? Did you find it useful?