Like a lot of other folks have said, I'd like for it to do well enough that I could be supported from it and do it full time, but not necessarily be super famous and huge! It took me a long time to figure that out, because when I was in HS and college it was like, yeah, of course I wanna be famous! But after having a bit of success with my first comic and meeting folks who have attained comic fame and talking with them, it turns out I'm much less interested in the monetary/fame aspects and really just want folks to love reading my stories and who come to love my characters as much as I do.
The weirdest thing that happened when my first webcomic got more popular was I started feeling expectations from the audience and it...kinda messed me up for a while! When you're new in webcomics you have a ton of freedom, you can write whatever you'd like and who's gonna say not to? But when you have that big following suddenly you don't wanna dissapoint them and whoof, it's tough to bear that weight.
So yeah, if my comic ever does make it big I'd like for it to be after I finish it at least lol so I don't have that pressure! XD