Someone needs to caption "I see what you did there" on that picture..
On a more serious note though, I love this place even though I'm pretty much a hardcore lurker. Almost all my posts are "light" (as in funny, one off, non-committal, etc), because while I like talking about things, I can't muster the time or trouble to have an in-depth discussion, which most here do like. Which is fine, I like reading most of the conversations here and if it gets too long, I can just skip it.
My point however is, I still see a big, close family with no forseeable troubles of decline in the future. The forum has also become more open and friendly to outsiders, so people can just ease their way in without having to post like crazy. Word of mouth is still the best way I think, the same way as you would expand a family: by connection rather than just throwing some strangers in. As far as people leaving is concerned, apart from new people I sometimes also see the "really old" ones coming out of retirement, so that should balance things out as well.