The most popular Red Sox message board on the internet has, for some time now been member only. This explains the history of the board and how it evolved to an application or sponsored only forum:
SoSH has steadily grown ever since. In 2002 we made the tough decision to close membership, requiring prospective new members to submit an application. This was done not to close the community, but to ensure that the quality of the discussions wouldn't suffer due to swift growth. This certainly wasn't the most popular decision we've ever made at SoSH, but it flat-out worked. Over the next two years we saw traffic increase exponentially - mainly due to non-members ("lurkers") stopping in just to read the threads. There are at least a dozen other Red Sox forums out there with anywhere from 3 to 10 times the members that SoSH has but SoSH still gets 5 to 10 times the daily traffic. If the SoSH members are the straws that stir the drink then these lurkers are the drink.
It looks like the Reds most popular message board, RedsZone, may be headed to the same model:
I'd create a new BB forum that is only open to the original RedsZone members and subscribers. "Standard" members could then be sponsored to the new BB forum by subscribers and original members while both the new, restricted BB forum is active along with the current, open BB forum. I would post on the current forum our plans and that the "Front Office" (for lack of a better term: admins/moderators) would also accept applications. This would run for a predetermined amount of time (a month or two). I would then close the current BB forum and make the new, restricted BB forum the standard forum. It would be viewable to ALL, but only accepted members could post. We wouldn't sponsor individuals any longer but rely upon applications to bring in "fresh blood" that the front office deemed acceptable. That part is the tough part, and we'd go through some growing pains, but it can be done (see SoSH).
RedsZone was my first internet experience with other Reds fans, and when I found it back in 2002 it was just a terrific place to be. I hadn't begun to blog and RedsZone was the first place I'd ever found that had all the Reds info you could possibly want contained in one place. The discussion was also extremely nourishing and interesting. RedsZone was different from every other message board I'd ever visited because the discussion was so elevated. It was somewhat imposing to begin posting there, but I did in May of 2002. While most of my 4000+ posts (amazingly nowhere near the top of the heap, many members have more than 10,000 posts) were on the non-baseball side in political threads, I still turned to the baseball side for Reds info. If it weren't for RedsZone and Google News I'd have a much tougher time finding things to write about.
But the place has really gone to hell in the last year. The core group of posters who previously had dominated discussion and elevated the level of conversation have begun to limit their posting because of the legions of posters who post on a MLB.com message board level. Anyone who's spent more than five minutes at the MLB.com board will know what I mean.
The poster that I most respected over the past few years was westofyou, a guy who has taught me a ton about baseball, and a person with whom I almost always found myself in agreement. He is now posting most of his substantial thoughts at Redleg Nation as opposed to RedsZone. Redleg Nation is much the better for his participation.
I view RedsZone's potential move to a SoSH model as a positive thing. But it'll be interesting to see the fallout from this one, if they do decide to go this way. The evolution of internet communities is a fascinating thing to watch in my opinion, and this won't be an exception.