That would be very sad. I would miss everyone and my avatar too. I might be depressed knowing that all the things I worked for on Gaia were gone. It would be a little like losing all your belongings in a fire.
I'm not sure what I would do afterward, but I'm sure I would do something. Maybe I'd find another site to waste time on, or I could just turn my attention to other things.
Honestly, it wouldn't really effect me, i joined 8 years ago, so i've pretty much lost interest in Gaia already, i just log in from time to time when I'm extremely bored, I'm sure I'd feel different if i still had friends, but they've all left for good~ sometimes I'm tempted to come back and start an art shop and try and make new friends here, but i never get around to it >3>;
I'd be sad, because I roleplay a lot on Gaia. And the community we have is really strong. I'd imagine we'd find another site, but it wouldn't be the same really. I'd also be upset, because I too have spent money on this site, and the fact that some day it will die and I wasted money depresses me.
I guess that's why I don't spend real money anymore, because I know it's going to happen someday and I'll look back and think of all the things I could've done if I hadn't spent money on Gaia.
I'd actually be upset. This is the one site I've stuck with consistently (joined in 2005 and never left), that has remained a regular part of my life. I've invested time and money here. There's a history. I'd hate to see it go. sad