I havent used this or tried since I dont have pay per impression banners on any of my sites but.... the idea would be (christmas themed) "Find the hidden Santa" You would make a small tiny graphic of Santa and hide them through out your site. Large forums like this would be ideal (hide in posts). Have your members count how many they find and then PM their answer after a week give a prize to the winners. I think this would work ok for large sites with pay per impression banners. Depending on your cleverness you may have very few people if any find them all and you will get tons more page views during that period. Does this idea sound good or bad?