I'm currently writing a book, which I'd like to self-publish and then sell on Amazon. I know my success is pretty much determined by whether I get a certain keyword or not, so I really ought to focus on making sure that I do.

So I ask, does the search engine for Amazon work in the same way that Google's does? Are factors like PR and backlinks relevant - or is it more to do with how many copies of each book they sell (which I find unlikely)?