How much does a fine artist earn?
There are too many people who are considered "fine artists" and little data to cover the complete spectrum. The overwhelming majority of "fine artists" barely earn enough from their paintings/sculptures to support a family or even themselves. So, they teach art or engage in some more lucrative aspect of art like advertising, illustrator, etc. Some take other non-art jobs to support themselves, much like actors do when out of work, and paint in their free moments. A few, about the same percentage as actors or ball players, make it to the big leagues of art and they can make good money. For example, Peter Max or Any Warhol or Leroy Neiman. But these are few and far between. I know hundreds of fellow artists and they all have a primary source of income other than their art...but they still paint because it is the love of their life. Me included.
Do you have to be an artist to join deviantART?
No you actually don't. My sister joined but is an artist. But if you wanna join and are not an artist it is completely fine its just that alot of people are artists some are poets writers designers just about anything creative or what you can do, i don't really know much about the site though but have fun!