(I am posting this on multiple threads as there are many new user names showing up and it is good information to know.)
If you would allow this slight interruption, I have a recommendation.
If the price point of a book is reasonable, you are wise to buy a copy. But, only if you have bought a copy of your own book. (And, if you buy your own book, follow these instructions...)
1. Go to the most famous book page that is similar to yours. (i.e. Stephen King's The Stand if your book is an apocalyptic or similar book.) Then, from that page, search for your book, click on the book page link and purchase a copy. By doing so, that famous book page will now display (people who viewed this book ultimate bought this (your) book.) Free advertising for your book on a famous book page.
2. Buying a copy of your own book then links your book to all that you have bought and a copy of your book will show up on those other book pages. (People who bought book A also bought book B.)
3. Find someone who buys a LOT of books. For example (and I am not posting this to promote my books) I buy about 4 to 8 books each week. If you bought one of my books (like one of the $.99 ones) then your purchased books and my purchased books suddenly become a hybrid category. This hybrid category usually shows up on book pages with very few sales. (People who bought books like group A (your purchased books) also bought books like group B (my purchased books.) ) This also keeps an active connection with all future book purchases as well.
4. Use your tags wisely. Use famous author names in the same genre. By using those author names as tags, your book suddenly becomes displayed on their book pages as similar items. Don't forget that you can select up to 15 then get someone to go vote on those same 15 (the count goes up by 1 on the tag vote.) You can then deselect your original 15 tags (famous authors that link your book to their books) and select 15 more. I did this using a list of the top 25 authors in the genre and now my books are on their pages as similar products.
Each of these will place your book in a position of visibility. Each position of visibility increases the odds that people will see and hopefully buy your book. But, they cannot buy what they cannot find. Having just a book page for the book buyer to find is like asking them to find a raft in the Pacific ocean... (big place, tiny raft, hard to find.)