Been mulling this one over a bit.
There must be a std list of reasons why people use forums and they may already have been discussed.
I didn't know this forum existed until I found it via search engines, so if my experience is common then getting people to hear about it is the first user/consumer problem. I don't know, but have the various "active" members who bought through dealers / importers pushed getting the forum known when others buy a Zed ? Similarly for after market parts and tuners.
Works two ways, those who get service from them go back and recommend, most likely in their opinion on the forum etc..
Having got the initial contact the problem is them becoming sticky for them to return. This is where the content and spirit of the forum comes in to play. Having a good and responsive set of experts is fundamental and especially when mixed with a good spirit. Change is generally good, things need to evolve and occasionally something radical needs to be added.
I agree somehow it is important to encourage the experts and recognise them, how I don't know, but keeping mgt items simple is usually a good place to start.
One thing that is always good to ask in these situation is "how do you know it has been and continues to be successful ?", is it number of posts / visits / amount of advice / greatest number of registered ids?
I'm relatively new to this but like coming back to browse / post, I tend to read on items and not post as I have nothing useful / fun to add. I may like to think I'm one in a million but as we know if you said that in China that means there would be over 1300 people just the same , but I doubt I'm alone / special in my 350z-uk forum browsing approach.