An example of how brands build fake reviews on Amazon
A friend of mine is in a facebook group that has lists of products you can buy, then 4/5-star review and get your money back. We're talking 10-100€ products.He goes as far as reviewing everything he doesn't buy there with less than 3 stars so his account isn't suspicious.Doing this he completely destroys what reviews are meant to be, not only helping shady companies but also hurting legit ones.