Not to be that guy, but it won't work. Their are people with no accounts, lurkers, those who live in private groups, and more. The thread doesn't even have a 100 posts in it, and the number of people on here is easily thousands. (Just check some of the bigger polls.) The fact of the matter is the number is constantly changing. The safest bet is a few hundred(s) who are constantly here, and then a few thousand who occasionally show up. Beyond that the only people who will know for sure are those on the Web Team.