If there's no legitimate way to find out who's the winner, then there's actually no point in doing it and no one will ever trust you
Do you want to propose a system?
As I posted in your other thread:
https://bitcointalk.org/index.php?topic=219632.msg2332147#msg2332147See also the followup post by tescomatty for some excellent ideas.
If you want, you can make this a fair and verifiable raffle.
Unfortunately, you have set up a system that seems fair but is completely unverifiable. Either you are giving free money to build a good reputation (which doesn't seem to be going very well), or you are running a puppet show and collecting all the winnings. Really there is no way for an outside observer to tell the difference.