I had wondered about that also, because it is very noticeable that many winners are first-time posters. I actually counted up all the winning posts, and a handful were from long-time members, like pmeek. What I did notice was that one winner copied and pasted the winning email notification. That email not only asks the winner to publicize the win, and provide a testimonial after the win is received, it also provides the winner with links to sweepstakes websites where the winner can announce the win! One of those links is to SA, so, that explains a few things!