For some time, I've been arguing that Amazon has a vested interest in making you a best-selling or top-rated author. You just have to know how to manage your books on their pages in order to rise to the tops of these lists.
Start by looking at your listed rank on your individual book pages. To understand what that number means, try dividing it by 32,000,000 (the current total number of books available on Amazon!). If your rank falls at 320,000 or below, you can take pride in being one of the top 1% of all books on Amazon. Do this whenever you start to feel discouraged by a lack of sales.
But before you let them go to your head, check your actual sales--weekly, by geography (print only) and rank over time. Access these graphs from Author Central, which will give you a more realistic view of how you are doing.
Today Amazon has added a new feature, Amazon Author Rank, the definitive list of best-selling authors on Amazon.com. This list makes it easy for readers to discover the best-selling authors on Amazon.com overall and within a selection of major genres.Did you get an announcement? If so, you are one of their best-selling authors in some genre. For example, my notification read:
1731 in Historical Fiction"
Amazon Author Rank is your rank based on the sales of all of your books on Amazon.com. Just like Amazon Best Sellers, it is updated hourly. The top 100 authors overall and the top 100 in selected genres will be displayed on Amazon.com. You can see your Amazon Author Rank trended over time in Author Central. You can find your Amazon Author Rank in Author Central under the Rank tab. Historical rank data is available from September 28, 2012.
Take encouragement from these rankings, but let them push you to do whatever you can to help your rankings along.