I've been thinking about what it means to be a successful Epic Fantasy author.
- Must have finished the Epic (not sure what to do about Robert Jordan).
- Standard of quality across all books.
Does publishing schedule come into it? I'm not sure. Tolkien had a pretty relaxed thing going on.
Note: Finishing the Epic rules out a few in my mind. Especially GRRM, JVJones, Jim Butcher (you probably have a different list). These are all successful (esp. Jim Butcher in "standard of quality" terms), but they haven't finished the story yet.