I wish more people would realize this. If there is a star/like/follow/review/rating anywhere on any web site, there is definitely going to be at least one service out there where you can purchase those stars/likes/follows/reviews/ratings in bulk.
If any end user can have an effect on something, then it is not a useful signal of quality.
If any end user can have an effect on something, then it is not a useful signal of quality.