I've known about SG for a while thanks to WillWheaton and his great writing. Finally got around to joining and supporting the cause, so to speak, only to learn that people (close to) my age and experience are leaving. Sad to see. You older / more mature / longtime / Suicide Girls - stick around! It is because of your life experience that some of us are here! So, don't leave us with the <19 y.o. and the >90 y.o (for those that don't put their real age)... stick around!
niobe:
I have been on the site for 7 years. I have seen so many people come and go. The good ones seem to be the ones that leave. 
artfulodin:
I used to say that about where I work (back when I'd been there for 5 years); then I realized I was still there. :-) So, I agree, Niobe, it can feel that way. However, some good ones stick around.