You could give away a PA 200 once a month, to be elgible you have to be a group member, that's currently 1360 approx, but it would grow as people as more people realized all they have to do iwin s join and post at least once. The winner could take the PA 200 or use the eqiv amount towards a bigger unit if he/she disires.

Come christmas time you could up the ante, that would keep them watching.