In Arthur Miller's "Death of a Salesman," the central theme revolves around the value of material success and the harsh reality of selling oneself in a competitive world. The protagonist, Willy Loman, exemplifies the pressures and disillusionment faced by those who measure their worth by their ability to sell and achieve financial gain.

The quote, "The only thing you've got in this world is what you can sell," encapsulates Willy's belief that identity and self-worth are tied to one's success in sales. This perspective ultimately leads to his tragic downfall, as he struggles with his inability to live up to societal expectations and the emptiness that accompanies his relentless pursuit of the American Dream.