For reviewers who post their work at WordWeaving, I also encourage them to post other places as well. Reviewers always retain ownership of their work. You don't have to agree with the review, but if it is done well it tells you some things about the book, its subject and presentation method and design. That to me is an invaluable time saver. I still prefer to form my own opinion regardless of what a review says, but for a busy person it could save me time if the title and the story are two different interpretations instead of what the title led me to believe.
Every writer is aware that reviews are subjective and the opinion of the reader.
And, that is who buys our books, readers. Those same readers who are willing to invest their time and money in our books. We owe readers the best book we can write. Believe me, if the reader hates your book, they won't be back for a second or third. I believe a newsletter that prints reviews certainly can provide the reviews to Amazon, although in effect that may cut down on the newsletter or e-zine's unique content.