I really have no idea. There is a wealth of information here, ranging from experienced members who are more than willing to share their knowledge to the rather expansive reference library. I find the the TOTM and POTM attracts a lot of people, even those that aren't very active on the board. I also think the "localness" (is that even a word) of the forum and subforums contributes to "real life meetings" which add to members familiarity and makes them feel a bit more comfortable about who they're talking to.
I like to think we also provide a welcoming forum for those lurkers to come out of the woodwork as well as new members to visit
