If you set it up with some revenue sharing plan and did all the work to get the advertisers it might be worth it for someone to invest sometime into a forum on your site but I agree with the others you would also need to spend some money on advertising to get the traffic and hopefully some active users.
So right now, what I would need is: 1. money 2. advertisment 3. traffic 4. active people willing to spend money to get a forum?