What do y'all think of this idea?

I had this idea yesterday. What if I did a monthly drawing/painting contest. Each contest would have a different theme. Everyone has a certain amount of time, I was thinking the contest would be posted on the 1st of each month and close on the 15th, but I'm open to different ideas. Each contest would have minor requirements (one month it may be that it has to be hand drawn, another month it might be that you have to use water-colors, etc.)
One more thing.The prizes for the winner would be:

1) They can help chose the next contests theme
2) They are a judge on the next contest. (I think I would be the other judge along with maybe one other.)

So what do you guys think of this idea? Do you like it? What would you change? Okay, bye!