On Amazon we know that a hell of a lot are fake.
On Trip Advisor etc you generally only get bad reviews as only pissed off customers bother to review, if its good then you think "Oh I must review this place" and 90% of the time dont get around to it.
Same with Argos etc....generally only bad reviews because if the product you bought does what you bought it for, you dont give it another thought!
I am looking for a particular type of cookbook and the reviews seem to be either no stars/one star or five stars!! Not much help really! In the last couple of years I have started to choose items that have a decent amount of mid range reviews as they seem to be the only ones that are genuine.