I agree that you can make a living from your pictures as long as they are pictures someone is paying you to take, in other words: commercial assignments. It may be architectural, portrait, wedding, etc. But you do not seem to be asking about that. As I understand it, you want to know if you can make a living solely from the sales of prints of your artwork that someone did not request you to make for them before hand. Someone pointed out Peter Lik, he makes a living doing that, but if you ask me, he is like Thomas Kinkade. In that I mean he takes photographs for the express purpose of selling to make a lot of money, but it lacks soul. Actual artists that make a living off of their work are very few in number. Andreas Gursky is in that realm, but he went to school and worked for years to reach that level. He doesn't sell a lot of work, but has gotten to the point where his prices are very high. Michael A. Smith is successful in this, too, but has a lower price range and must work very hard in the marketing department to get the quantity sold to live off of it. Two different routes, but the same goal. As I said before in my earlier post, most artists that are getting in the big galleries and museums and sell prints and books of the work they want to do are university faculty. I know, because I talk to them at Society for Photographic Education conferences every year since I, too, am on faculty.