It's gotten to the point where a product with thousands of reviews and an average 4.5 - 5 star rating immediately raises a red flag with me.

And Amazon appears unmotivated to do anything about it. As a personal example, I had purchased a mouth guard that had over six thousand 5-star reviews. It was listed as high quality, FDA approved, etc. When I received it, it was a piece of plastic junk with inkjet quality instructions in English and Chinese. Along with it came a note promising a $10 Amazon gift card if I left a 5 star review and emailed them proof of it.

I took a photo of the note and forwarded it to Amazon expecting some action - instead I received a canned response about "we take these issues seriously". A year later, that seller is still there with dozens of products, all with thousands of 5-star reviews.