What an interesting topic! It's nice to see so many different people doing the same thing with love.
I'm a university student of geology and somehow manage to support myself and my retired parents by doing something like freelance illustrator, but with three main companies who mostly commission me - my home faculty (science popularization projects), an art studio which borrows me to various customers and a children magazine.
(That's why there is no way for me to draw webcomics anymore as I have to make my top priority to financially support my family, which is kind of painful, but priorities are priorities.)