An important factor to note is that it's rare for anyone to sell a first novel written before they turned 30-35; long-format fiction tends to require a bunch of experience of human life that takes time to acquire. So your average mid-career novelist is in their forties to fifties!
Charles StrossI'm an individual. I do not want to get into a pissing match with an organization that is a de-facto gigadollar-turnover multinational!
Charles Stross