My site hosts a number of riddle games where players have to solve a series of riddles first to win a prize. The prizes are put up by sponsors and in exchange i design the riddles so that the players have to visit the sponsors site in order to solve the clues. This gives you targeted traffic to your site with multiple hits from each player. The next 2 sponsors get this service for free. All you have to do is put up a worthy prize. The best two prize offers before the end of the night wins this service for free. URL is in my sig.