Actualy, the total number of respondants of a poll does *not* need to approach the total number of BBS members, provided of course, the goal is to measure the BBS members. If that's the case, then based on how confident you want the result of the poll to be, (e.g. 95% confidence) and how accurate (+3 x%) you can actually mathematically work out the *exact* number of answers you need for a fairly good and reasonable answer. And typically yes, the number of poll respondants are the tiniest fraction of the membership of the sampling group. Strange but true.
Calvin