Paul,
This is a good idea, but I have a few things to add to help make your idea even more profitable and help everyone with coming up with even more money-making ideas. First if you find someone who is a dealer or become a dealer yourself for Kaeser and Blair (www.kaeser-blair.com) which last I knew was around $80 to become a dealer, they sell promotional products and they have business card magnets for around $320 for 500 and if you become a dealer for $80 or so, you would have invested around $265 and that would be a savings of around $250 which means if you still charge $100 to each advertiser you would then profit $2,680 only $250 difference, but $250 pays my heat and electric bill in the winter, so it helps. Also just to name a few other simular ideas, you could use business card calendar magnets around $.040 each, or you could use monthly planners around $.075 each. Anyway, I hope this information may help someone make some more money.