Hi Sue - thanks for including Freelance Writers Den in your post! We actually specifically added to our guidelines recently that we do NOT want our members soliciting other members via email or PMs, or viewing other writers as their prospects for active marketing. We're trying to keep writers focused on finding business or publication clients! Since they are the bulk of the market...and it bugs members to feel like their membership has just made them a target of pitches.
That said, we do have a specific "referrals and job leads" forum that does get some posts from writers passing on gigs they don't want to do, or looking to sub out some work. And that's our accepted method of sharing those opportunities. I'd agree it's not a ton, and definitely not the main purpose of the group -- no one should join in hopes of getting referred gigs -- it's a learning and support platform.
We do have our exclusive Junk-Free Job Board for members, which culls from dozens of sources and cuts out all the $5-a-post type baloney you have to wade through elsewhere. I post many referrals to the community of gigs I'm passing on, both in that forum and on our board.
I recommend freelancers join forums and groups where their prime prospects hang out, rather than other freelancers, for prospecting amongst the membership.
I agree with you about looking to paid communities rather than free ones -- LinkedIn's forums to me, for instance, are a huge waste of time as so many people within the freelancer groups are gadflies/wannabes or otherwise not knowledgeable, and certainly not useful as prospects.
Again, thanks for including the Den --