I've been active on forums for many years, and I've seen a variety of models and interests. These include porn webmasters, hosting, domain sellers, hippy, general, casino promoters, and a variety of others. I've even created fake forums to generate traffic to sponsors and other sites I own. One such is
Net Barons. and today is the first time I've visited that for many months. I've moderated and owned a number of forums, and I try to use my signature for my own purposes. I have never rented the space to a third party. It is unfortunate that the promotion that generated me the most money was in the on-line casino industry, and one signature on a porn webmaster board was earning £2,000-£3,000 per month.
The problems that I have seen have been many, and the worst for me was the attempted signups by ref link spammers for the pharma and porn industries. It is hard to control a flow of 500 or so signups every day, and one just ends up closing registration.
Another problem comes from cliques of long term members who try to dominate new members. This can drive away potentially useful contributing members. Often they start flame wars, and whilst sometimes these can be entertaing, often they are destructive for the forum.
I was also very active on a paid to post forum, and this can be fast flowing, and generate good revenue for the forum owner, but it does encourage spamming, and it is often difficult to maintain a sensible discussion.
One formula that does seem to work is to have an open section with a number of boards, and a closed section that is private and invitation only. I'm a member of a casino forum that has this structure, but I've rather neglected it of late,
Bitcoin Talk has a fairly difficult problem. It needs to be international, but it needs to have the main boards in English. Keeping the English boards clean can only be managed by active moderation in my opinion. It would also appear that it needs the traffic generated by the bounty hunters, and they seem to be very low level members in the main, and I believe that they should be contained in their own sub-section of boards.
This post seems to be going on a bit, so I'd better close it now.