@codinghorror gave me the idea for this thread in his reply here
What factors do you take into account when joining a forum?
What type of forum user are you? Are you a lurker? Someone who joins a forum, asks a question and then only returns for the answer or to ask another? Are you a core member of a forum who logs on daily and reads a large number of posts? Or one that goes out of your way to answer? Perhaps you use forums to promote your goods or services?
The purpose of this thread is to try and get us to think about, and how we can cater for, the different types of forum user (of which there are surprisingly few common types).