People who prefer facebook and dont do their research on forums are novices. PERIOD
Pretty much this. I'm on Facebook a lot because I use it for work, so I tend to also answer questions and frequent a few groups on there. But the fact of the matter is that 99% of what I've learned (and continue to learn) has been from forums. The other 1% has been from blowing up Dowdy's inbox on Facebook.
The single biggest advantage that forums have, and one that I think more forum owners should focus on, is longevity of information. I've read build threads that span back 10 years to people raving about bioballs. But that same thread will go to the present day when they've changed over to different systems, and documented their experiences along the way.
Forum owners love to talk about community, because that's important to them. But to new people coming into the hobby, they want answers. Facebook tends to be a faster way to get them, so it's become more popular. People want instant gratification and as a rule, people are lazy. They're going to flock toward whatever is the lowest barrier to entry.
For example: Imagine not knowing what a hydroid jellyfish is, and then trying to Google it. I work on the Internet. It's been my experience that most people are terrible at using search engines properly. So instead of joining a forum, trying to find the right sub-forum, posting and then waiting, they turn to Facebook. They post a picture and get an answer in a few seconds. 3 out of the 5 answers that they get will be good. 2 of them will be someone saying it's aiptasia or copepods. If the aiptasia or copepods answer comes first, the new hobbyist will leave Facebook with their newfound "knowledge" and pass it on to someone else.
Reef clubs and forum owners have almost identical challenges. They typically do a terrible job of marketing themselves because what they see as the selling points are not at all what a new "customer" (new hobbyist) would want. Facebook groups are easy, accessible and exist on a platform that the person probably already uses. That's a set of tough challenges to overcome.
