Amazon rankings, like age, mean nothing.
(1) SUFFER IN SILENCE: 17,071
(2) COOKIN' FOR LOVE: 31,325
(3) THE CIRCLE OF SODOM: 154,157
(4) INFERTILITY SUCKS: 176, 632
(5) WAITING FOR THE WORLD TO END: 230,121
If you haven't been by MJ Rose's blog lately (well, first of all--shame on you) then you should stop by. She has a great post (with data provided by writers) about the influence (read: unreliable influence) of sales on Amazon rankings.
Here is a snippet:
"Last Thursday, one of our books zoomed from a sales rank of 32,154 to 872, peaking at 665 on Friday. How many copies did we sell in total last week? 17."
And best of all--for those folks who want to attend a "seminar" on how to become a Amazon bestseller, she recommends this:
". . . you can take that same amount of money and buy a whole lot of your own books all at once, in the middle of the night where there's not much book buying going on. You'll get your low Amazon number and you'll get a lot of books for your money, which you can use for promotional purposes."