Think about it. Let's say we bought a big studio with enough capital to turn out 20 movies a year. And let's say we started the studio by signing up eager unknowns under, say, 7-year contracts at $50,000 a year. By the terms of contract, the actors/directors would be barred from making movies with any other studio, and would be required to work full-time on our studio's movies.
Naturally, most of the talent would turn out to be of little star power. But if just one in twenty (or whatever) actors turned out to be a big box-office draw, we could put those actors in movies and keep paying them just $50,000/yr for the life of the contract while raking in money. Since big stars can demand $1 million or $5 million or $10 million or (way) more on a picture, think of the huge money we'd save.
Why don't film studios do this anymore? The fact that this would radically reduce earnings inequality and increase job security in the acting business is a major selling point for me (it acts as a form of social wage insurance) - but I don't see why it wouldn't also be very profitable.
SA