Was going to post this via IM, along w/ a couple of questions about financials. But since this is more or less a public discussion now, I'll post some thoughts here...
One of the non-automotive forums I support has a 'monthly' plan, with a $4.00 / mo. recurring charge. It costs more than a yearly, but still grants you the right to post items in the classifieds section - and there's a *lot* of sell / swap activity (e.g.; lots of eyeballs on the site), so those who have trouble coming up w/ the yearly in one shot can still post classifieds to the site, knowing they're paying a little more for the privilege of having a national (actually global) site dedicated to similar-minded users (and fee-free, unlike the Bay.)
I know there's not a lot of classified activity here, but you get the idea. Which brings to mind the question - what are supporting vendor fees? I know three at a minimum that post here fairly regularly (two have fairly large e-commerce sites of their own, as well as brick/mortar. Since they're using this site to generate revenue for their own (and I support one of them w/ my own business), they s/b paying a decent vendor fee, IMHO)
Another site restricts requests for (urgent) help to supporting members of a certain tier. It's an automotive site as well, but the platform in question is in its fifth (?) generation and still being built - so they have a constant influx of new users / new vehicles, to supplement the ones who finally retire their old ones.