I suggest for having a reseller hosting contest for one or two years. And Second suggestion will be a domain registration for one or two year. These two contest will surely drive traffic and posts on the board, and there are no hesitations. But contest rules should be like the past one mean, by refferals, not by posting. This will also help you to get the backlinks and posting will help you to have some spams on the board. i saw the refferal programme is the best way although.

Shawon