Consequence of gamifying things (reviews, stars, upvotes, retweets) means everything is gamed.

I'm reminded of a post from a few months ago: a guy had a massager who got annihilated by Chinese competition because they knew how to exploit Amazon's systems.

I find if you read some reviews with cynical eye you can still get quite a good idea. I mean the "great 5*" ones may be fake but the "quite good but terrible service 3*" usually are not.