Usually, they will announce it on the front page of this thread AND the front page of gbatemp.net. Winners are also PM'd personally to get their shipping address'.
Loser bitch and moan after the results come out because usually the winners have low post counts or they lurk for years and only come out to win these events.
I dont think being an everyday active user is a requirement for this event.
I think, work, originality, and quality is what decides the winner of this contest.
If how much activity was a decisive factor to winning this, then there are probably a handful of users who would win just by uploading a Penis with a Christmas hat on, made in Paint.