So the writers do not work for the shows? (I dont watch tv, just trying to understand)
Sometimes the writers work for the shows and receive a salary, sometimes they are freelance and only get paid per script. In movies they are all freelance.
It really doesn’t relate to any other business, though the business model for movies is nothing short of brilliant: people are hired and come together to make a single product and then disperse when the product is complete. No matter how good a job they do, when the job is over, it’s over.
However, there is enormous money to be made in TV. Law & Order has generated well over a billion dollars in revenue over the years for the network.
It is not unlike any other business in one respect: the writers, actors, producers, directors, etc. etc. sell their product for as much as possible. It helps to think of them as subcontractors manufacturing components rather than employees.