When you're a writer on a show, your job is to write in the show runner's voice, really.
I think a writer's first job is to entertain, even in novels: to tell a compelling story that pulls the reader along toward an end. At the same time, the best stories are character-driven.
When I sold my first book, 'A Conspiracy of Tall Men,' it was part of a two-book deal. It wasn't hugely lucrative, but it was enough money for me to quit the paralegal job I had in San Francisco.