The problem with five point scales for reviews is that the star ratings mean such different things to different people. Apparently, sales dip if a book receives 'only' three star reviews, suggesting that a three star review is seen as far from an endorsement to buy. Unfortunately, a lot of people giving the reviews don't seem to believe this. Here are some comments from three star reviews of my books:
"Ripping yarn... I read it prior to holidaying in Kuching and it made a very entertaining and informative prelude to our travels. Worth reading regardless, but a great way to get some context if you're travelling to Borneo." The White Rajah reviewed on Goodreads (average rating 3.8)
"It has a personal narrative that moves beyond the preconceptions of LGBT fiction and approaches that ranks of Sarah Waters in storytelling." Cawnpore reviewed on Goodreads (average rating 4.29)
'Goodreads' is an excellent site and well worth a look. I think reviewers there are more careful with their ratings than on Amazon. The lesson, though, is not to look at the star rating and move on, but read the review. (That said, Cawnpore is currently rated at 4.8 on Amazon.uk.) There's a lot of books out there and it is worth making that bit of extra effort to find the ones you'll enjoy – even if they're not mine!
And yes, although some authors claim never to look, I do read my reviews. I welcome all feedback on my work, either here or on Amazon or Goodreads. Oscar Wilde said, "There is only one thing in the world worse than being talked about and that is not being talked about." When it comes to book reviews, he was definitely right.