The very nature of a forum / bulletin board is to have people participate. We realize that some people prefer just to read the topics and are hesitant to speak up, if everyone did that, there wouldn't be much to read.
Here are the participation requirements:
If you are a paid member: There are none. We want you to post. We hope you do. But if you pay for membership we're not gonna kick you out because you're shy.
If you are a non-paying member: You need to make at least one post within the first 48 hours of joining and make at least one post per month to remain a non-paying member. If you're not going to post, why bother to join? Guests can see almost everything that non-paying members can.
To be a full paying member of the forums will cost you three whole dollars per year.