Cry, I fear I might not have all the answers to your questions. As I have mentioned in an other thread a while ago, things are different from other forums. As for activity this place seems low. But there are a lot of inactive (lurking) visitors as you can see on some of the threads (see screen shots) and yes you are right. From my back panel I can see huge hit counts for this web site.
I can only assume that there are possibly a couple of reasons for having more readers than posters.
I think the main reason is that we have already compiled tons of information and that due to the clearly visible sections people are able to pick up information easy and fast before they leave the same day.
In many other forums where the sections are less fragmented, if there is any at all, posts go all into fewer, thematically more generalized sections. Consequently information is harder to find which in return causes people to ask more, even though topics have been discussed more than once. Simply put: I think the less sectioned and the more general a forum is the more activity you will find.
An other reason I can think of is that this forum is biased on engine topics, which in its' nature is more limited than a Forum of a more "general discussion of a whole car" place. There people can talk about all kind of issues which is a good thing too.
I was aware about this a few years ago when we had just the engine and trans sections. So I created a few more sections like this one here for instance. I was hoping to make this forum attractive for a broader range of people, rather than engine heads only.
These forums have grown really big and represent a more attractive place to all those who want instant solutions to their problem or those who just want more social contacts. It's hard to make people being part of a more quite place like this one and hoping to populate it more. I'm not really into this kind of acquisition. Off course I would love to see more people come together and chat but it's just the way it is. Recently I have very limited, almost no time to be active myself since I'm very occupied w. my work.
Anyway, meanwhile I'm O.K. with how things are. It is more like an archive or a wiki where there are more readers than active participants. Sometimes less is more and I really appreciate all the great posts and tutorials that can be found here. People have put a lot of time and effort into their posts.
The fact that this forum appears pretty much on top of search results might be a result of how these engines have validated this site as a serious source on the topic.
Therefore I'm really thankful to see you guys putting your time and effort to share your experience and photos.
Keep on the god work and thanks again