Excellent point, Desmond. It is mainly an IM phenomenon.

Obie - some ideas:

-48-hour contest for most sales, highest conversions, coolest promo video.
-Flip camera
-headset/mic

Again, going with cash prizes isn't original, but you can't go wrong if you're generous with the prizes. Remember, your front-end profits are insignificant compared to your back-end and future profits.

Curtis