Here's my take on the reviews at Amazon.
Please write more than one sentence: Neither "This book is great, you should buy it" or "This book
, run far away" are at all helpful. Take a few sentences to say WHY it's great, or WHY it
. But, even so, not everything is all bad or all good, so if that's all you're saying, I ain't listening. . .
But don't write too much either: I've seen some reviews that seem to be nearly as long as the work they're reviewing. They'd better be really well done or I'm not going to get past the first couple of paragraphs.
Please don't tell me the plot: I've seen reviews that basically say, "First they did this, and then that, and then they had to do the other thing, so in the end xxxxxxx." Not helpful -- and why should I buy the book when you just told me how it ended?
I will pay the most attention to a review that is well written, explains what the reader liked and didn't like about the book, and seems to provide honest feedback. A nebulous and subjective call, I know. If I'm impressed by a review, I'll often also look at other reviews by that person to see if, by chance, they've reviewed another book I've actually read, to gauge whether or not our tastes are similar. And maybe to go check out those other books as well if it seems like we are simpatico.
I'll pretty much automatically discount any review that seems to be by the author or -- since I now recognize some 'other' indie author names

-- by another author where it seems like there could be quid pro quo. Especially if said review is a five star shower of praise.
I'll put MORE stock in a review written by a KindleBoard member because I feel like I 'know' them better. I probably already have a feel for whether we like the same kind of books and so can judge if their assessment might match my own. Though I won't automatically buy it or steer clear just because it's a KB member review.
For a Kindle book, I do want to know if there were formatting problems. I read one (a book, not just a review) that had no paragraph indents. That was hard to get through and speaks of inattention to detail in producing it in e-format. If I saw that such a problem existed in another book, I'd probably steer clear -- even if the subject matter interested me -- until I saw that it had been fixed.
My opinions only, obviously.