I enjoyed reading this post. It gave me much to think about as an Amazon reviewer. I have my own system of stars and try to remain consistent. I do read others' reviews and this will influence my kindle purchases. If a book has high star rating and the premise of the book is interesting, I take a second look and decide on a very personal level whether to purchase or not...even my kindle freebies are held up to this level of scrutiny.
I have read the "how-to" guides for book reviews, especially when I attempt to review a new genre or type of book, for example...I researched how to review a cookbook as I have many on my kindle to read and would like to delete the clunkers. It gave me much information and I apply much of what I learned to each genre in kind.
I think writing reviews is important to a reader and will influence others to find new books. I also think that an author should take reviews with a grain of salt. It allows them room for improvement, builds upon the depth of the characters they write and can develop a following on sites like Amazon and Goodreads, however, it can also negatively impact an author if a review isn't realistically written. It could be either too highly praised and not to be fully trusted, or too vague, such as the examples in your blog post certainly are. It can also be purely negative and even harmful to a writer. I try to balance my reviews. If I can't help but post a negative review or give one star, then I try to state why. At times, it is simply because I chose unwisely, a book that I would not normally read and found it wanting. I hope these comments assist others in writing reviews that truly reflect a personal opinion on a book actually read for content and enjoyment.

Hi Darlene - thankfully your diligent attitude is more typical of that found among members of Goodreads!

I came across an analysis that suggested a lot of people check to see if a book has a good number of positive reviews - but then they read the negative ones to see if there are any reasons why they personally would not like it (eg. bad language).

From an author's perspective I find reviews invaluable.

Positive reviews provide MOMENTUM - they are uplifting (almost to the point of tears!) and spur you on to keep writing.

Critical reviews provide DIRECTION - they help you to adapt your writing to better please your readers (although this is sometimes tricky to achieve!).

Negative (as opposed to 'critical') reviews can certainly be demotivating - although I suppose it is the risk you take - especially when you are asking people to part with their hard-earned money.

I do think it is a shame that the Amazon system appears unable to distinguish between considered reviews and those that are spammed/paid-for in vast numbers - however, I imagine the discerning reader is able to see through the latter.

Recently someone on Amazon questioned why I have many more fictional books with fewer stars than non-fictional books. Personally, I think this makes sense since most of the non-fiction books are chosen because of personal interests.

On the other hand, fiction has many different facets that affect my interest. The characters themselves are first and foremost, followed by plot and believability.

I am constantly amazed by some of the reviews on Amazon and Goodreads. Sometimes, I truly wonder if the reviewer read the same book I did.

Yes - that's a good distinction between fiction and non-fiction. With the latter you can be more confident of what you are buying.

Also the way different people react - I recently got two successive reviews on Amazon, the first said, "The weakest plot in the series so far" while the second wrote, "The best plot in the series so far" !!!