I own and run a forum, it takes a LOT of time to gain members and have your site expand through word of mouth. I have 700+ members to date, with 5,000+ posts. I'm the #1 site for a few search terms and I still only average ~120 unique daily.
I would suggest making your forums unique. You MUST have valuable content and it needs to be able to be searched by engines.
Goodluck.