I have a gaming website,
www.cagclan.com and I don't use VBSEO or DB Techs version of it and our site is very active.
What it comes down to is how you advertise your site, word of mouth and how user friendly your forums are to your guest more importantly.
I have also used this site,
www.top100clans.com to help bring traffic to our forums. It is a voting script website and I would say about 70% of our forums traffic comes from these guys alone.
Unless you are a big company or need to make money, I personally do not see the need to spend that kind of money for SEO crap.
People who look for what we have on our site find it easily just by googleing it. We have no problems getting new registered users who said all they did was googled for certain keywoards such as #1 clan, xbox clan, blah blah blah and they ended up on our site because their search results had our site in the 1st or 2nd page alone.
If you need help my Man, let me know, visit our site and I can share more ideas with you to get your forums going.
We have well over 3500 registered users and most of them are actually active. It also helps if you yourself interact with as many of the registered members as possible in one way or another.