The author of my current favourite webcomic, Tom Siddell (of Gunnerkrigg Court), recently quit his job and went pro. I'm sure that's usually a nervous decision; the number of slots available to support culture in our society is probably limited, and while in one way or another hopefully most of us are producing culture in some sense even if it's not our job, trying to get enough income to support it suddenly turns cultural production into an abstract competition with invisible others; it's a highly elastic competition in that people can choose how deep to dig into their pockets at any given time, but also likely a fickle one. It's something I would be reluctant to rely on as it's something I personally am not in the habit of deeply supporting; I have very occasionally bought collections of webcomics, and once or twice over the years I subscribed to pay ones, but the margins from people like me are fairly slim. But then, I suppose slim margins for a lot of people might add up to making a living? There have also been a few opensource projects I've donated to (most significantly to vim and OpenBSD); I sometimes wonder at the economics of those projects and donation/cultural economies in general.
Barring the ability to write a column (which might be a lot of fun if it were on politics or philosophy), I don't have developed-enough skills of any sort that I likely could do that kind of thing myself, but I admire the bravery of those who try, and wish them well. It's particularly impressive when they live in expensive places and still make it work.