|She hates your book more because she expected to like it -- neil conway / Foter / CC BY|
So what does this mean--well, first off don't rush to assume your worst critics are competitors, ignoramuses or the habitually grumpy. Surprisingly (to me anyway) most reviews were found to actually be feedback from legitimate customers. About 95% had bought the product through the site and some of the rest may have bought it elsewhere and gone to the site to review it.
But also don't think this means everything in the reviews is gold, because the bad reviews are generally from customers who don't like change, and it is inevitable that a writer will create different kinds of books during their career. So they are a small number of people with a specific perspective, but to the extent you care about their point of view at all, you have to try and work out where they fit in with your other, less vocal, readers.