I think the 2 year time frame is accurate, but not just only for this hobby, but any hobby. It is called "churn." If one stays for that 2+ years, then they are in the hobby. The rest are just dabbling. Not sure if they are really serious reef keepers or not.
I think there are a lot of people that do not fully understand the time, effort and money that this hobby really requires. Add to that some bad advice from a LFS, lack of research on the critters you want to keep, lack of patience and some bad luck and what do you get? A Death Tank. If everything you put into a tank dies (or is eaten), if is tough to carry-on.
Having the board allows both the newbie and the more experienced hobbiests to both give and get honest advice from each other as compared to the advice from a LFS that has a vested interest in seperating the hobbiest from his/her money.
We will always have the ups and downs of the business cycle and we will always have people occupying their free time with hobbies. That is not going to change. We also know that the really good hobbies are the expensive ones.
We, my friends, have just gone crazy for those critters in those water filled boxes.
[ May 25, 2001: Message edited by: JohnD ]