It depends on the efford the webmaster puts on it, as a baby, every site needs caring, feeding and cleanning the shit(ty people), also new clothing and of couse ! Gifts ! ! ! :D (for us, not for the webmaster ! :P )
I m comming for a dying spanish community, it is called www.laneros.com, it began in 2000 as a place for LAN-parties, it grew a lot, but now most of its casual members are shifting to social networking and dont visit the site anymore, even their own creators have chosen this trend.
Every single month fewer people visit them, now it has only got 7.500 members "actives" when others borning communities have 66% less people and about 5 times more "actives". In numbers it is like a 390K members and only 7.500 "actives", while the other has got 130K members and about 34.000 actives.
It is very sad for see that happen, but i have seen also others communities and dont die, it depends on the caring the babysitter takes ja ja ja ja XD XD XD sorry, just kidding.