I haven't won contests from various casinos for many years, although I take part in all possible contests. I sometimes think that some competitions are not conducted fairly.
You have not won any contest and that's why you believe that some contest are not fair and are being manipulated at the casino end. You could be right but most people who never won any contest think same. We need to understand that these contest at the gambling site are won by very few people and most people will never win them. You can only win if you are lucky, if you not lucky then don't blame the system.
I agree with this, even in contest you also need a luck for it also you are not the only one competing on the contest there's also a number of participants which will lessen your chance on winning. In short more participants on the contest = low chance of winning.