One of the authors I follow recently sent an email to all her fans to explain why book reviews are important to (self-published) authors. According to her, although many authors never make a fuss about reviews, they ultimately appreciate them because it means their books are being read.
However, the "stars" rating system is a different issue. Some (self-published) authors may become seriously concerned if their books receive less than three stars in reviews, because, in the words of this author:
"There are a number of bargain book blogs and mailing lists that can get you good sales when your book is listed there. Most of these sites take books only once they've gotten a certain number of reviews of a certain average star rating. Mostly, this is four stars.... From a business point of view, reviews are of more immediate importance to a self-published writer than a trade-published writer. An X number of reviews means you can get picked up by these blogs, and this means more income. This is why there is such a lively informal 'trade' in four-five-starred reviews by authors for other authors."
I may sound naive, but I truly believe the purpose of writing book reviews is to offer honest and constructive criticism to authors while sharing excellent books with other readers. I personally do not believe a book can be rated in any way, as it means differently for different people. Neither do I believe that rating with "stars" or other symbols needs to and/or should be part of the process of reviewing books. Instead, I think book reviews are to help readers understand a book and to let authors know that someone does appreciate their work. This is why platforms such as GoodReads are important where readers can review without rating.
And I sincerely agree with this author's view: "I especially wish that these ad sites would drop their star rating requirements as a lazy shorthand for 'quality'. They want the author's ad money, and don't want to look at the books themselves, so that's how they judge whether a book is 'good enough' for their site. That's what it comes down to."
How do you feel about book reviews? Do you as a constant reader use the "stars" rating system? What are your usual criteria? I would very much like to know.