Does promoting on forums really help? I think they would because otherwise they wouldn't be in existence. Does it help with SEO? I was told you have to write something compelling and ignites discussion otherwise people won't look at your posts. What about paid forum advertising?
Yes, it creates a preferably good backlink which could help your site in many ways. They are not here for nothing, they serve a purpose of getting you or people who advertise on them visitors.
About half of my members come from forums. Another half from google. For a roleplay, it's pretty odd to have so many come from google--the vast majority come from other forums.
I just started and AdWords campaign running as low as $0.0075 pr. click! I don't know yet if it will get any users but at that price it is absolutely worth the try.