How much do writers make anyway?
How big an advance can an unknown novelist expect on her Debut book?
Justin Larbalestier asked a lot of novelists. Overwhelmingly, the answer seems to be - not much. You most certainly can't quit your day job banking on that advance.
John Scalzi initiated a good thread in Metafilter on the subject. In his weblog, he had earlier suggested that expecting to make a living writing -specially if you are a genre fiction writer- is unrealistic. He also has good pointers for those writers who aren't scared off by such assertions!
I can't conclude this post without referring to this awesome interview on Slashdot, in which Neil Stephenson claimed (in answering the second question) that unlike 'literary fiction' writers, sci-fi writers actually make a living writing. He was probably talking only about well-established writers.