Concerning certain users winning multiple times, there is still an element of randomness in winning competitions unless stated otherwise. So it's possible for one user to win multiple times; however, we will monitor if certain users are winning too often.
This doesn't mean that if you have been lucky to win a competition, you can't win again; you will have the same chance as everyone else.
We are simply going to monitor if the same set of user names keeps getting drawn. The goal is to have a balance of randomness; however, make it fair for all users.
At the end of the day, we now have 1000+ users entering each competition. The best way to increase your chances of winning is to simply follow the requirements in each post and submit as mentioned in each post.
I notice upwards of 100+ users who will not follow these clear instructions, then complain that they never win.