Cash & gift certificates are always good.
A tv means somebody needs to pay shipping charges, and people not in the continental US are often left out.
Personally I hate it when feeds & hosting are offered, since we already have hosting, and I cant give my members feeds for a month & take them away; so they feel like gateways to a purchase, not a prize.
comped rooms & flights are always good though, since it's those expenses that keep some people away from them.
How about a big bar tab at internext?
