It could be that the active community is too small for something like this to work right now... but I guess you will be able to gauge from responses.
Personally, I wrote the game and even _I_ wouldn't chuck $20-30 a month away on advertising right now.
Yeah, but you have better places to spend your money.
Money has never really been an issue for me either way, and even when I do buy a game, it just sits there 95% of the time. That said, you're probably right. The community is pretty tiny right now and even if lots more people decide to participate because they fancy the prizes, there's still no guarantee that I'll get the results that I see in my head. I might just wait until the next major update to kick things off and get people out there showcasing the new features.