From time to time I get e-mails from authors whose books I review on Amazon and I always think it's nice of them to take the trouble to contact me. I had one yesterday from someone well known in the chick lit field who said reading reviews of her own books was much like 'sticking pins in your eyes' but that she'd been cheered up by my reviews of her recent books. I can understand how authors must feel and in general even if I didn't like a book I'll highlight things which I thought were good so that a review isn't all doom and gloom. I do very occasionally write one star reviews but again I will say what I did like about the book rather than just saying it was unmitigated rubbish. There is always something you can find in a book which was good.
I even gave a book 3 stars because it was a long time since a book had annoyed me so much! Other people gave that book everything from one star up to five stars so it was obviously a book that had a mixed reception.
Why do I write reviews? Because it's the next best thing to writing books and because it often helps me organise my thoughts about what I've read. It means I'm writing virtually every day which is good practice. It's also interesting to watch yourself climbing up the Amazon reviewer rankings - currently 256 and climbing. Being higher up in the reviewer league table does attract its own problems because people are apt to post stupid comments on the reviews or give you a spate of 'not helpful' votes for reasons which aren't always obvious. I find it interesting to watch.