While the vast majority of Kindle authors are truly amazing people, there is, like with all things, a darker side to Kindle publishing. It is an underground war where a few authors feel that the only way they can get their books to sell is to buy or post negative book reviews to other writer's books.
Buying Negative Reviews
Did you know that you can buy negative reviews on Fiverr.com? Just as some authors will buy positive reviews for their books, a small amount of authors will also buy negative book reviews for their competitor's books. I have had this happen to me with a certain genre of books I wrote and it has happened to plenty of other writers, as well. As soon as your book starts selling well, you will suddenly get slammed with negative reviews so that your sales drop and the other writer regains her spot on the charts.
Posting Negative Reviews
Since many people write under a pen name, it is not difficult for a writer to post negative reviews of the competitor's books. The review, when accepted by Amazon, will appear under the person's Amazon account handle.
Avoid the Downward Spiral
I am against posting negative reviews to hurt the competition, just as I am against buying positive reviews for my own books. While quite a few business writers have admitted that they have bought positive book reviews for their books in order to get people to buy them, it is an act of dishonestly that angers many readers.
As soon as you start attacking your competition, it is a downward spiral. You will be wasting your time, your money, and your energy on something so damn stupid that it belongs in the middle school cafeteria. Just think of how much writing could be accomplished if these people would return their focus to the writing trade?
How to Deal with Fake Negative Reviews
There is very little you can do about negative and unwarranted reviews of your book. Some writers have gone as far as buying positive reviews to counteract the negative reviews. The rest of us have simply learned to develop a thick hide. All books, no matter how well written, will get negative reviews. The negative reviews that are bought, however, often get called out by other readers. I had this happen to me with one of the books I wrote under a pen name - my book had gotten a very strange negative review and another reader corrected her on it.
Ultimately, the system of reviews does correct itself when you begin getting honest reviews from readers. It takes time and patience, but if your book is well written and readers find it interesting, they will begin to stick up for you.