Amazon Rankings

So it has been quite awhile that I have checked my Amazon rankings for Angel Academy. The book continues to do well and I have multiple avenues of marketing promoting the book. Today when I went to Amazon, something new greeted me on my book page. There are new rankings past the top 100. Like most authors and readers out I wonder how a book is doing after it has released. What keeps a book on the top 100 or top 1o?
So it is kind of cool to look at the different categories and know that there are literally thousands of books in one category.
Screenshot 2014-11-24 10.23.17
Here is my screenshot proving to the world that I am a one time #3 best-selling author.