What did Willy Loman sell in Arthur Miller's Death of a Salesman?
It is an interesting (and ironic) reality that, in a play called Death of a Salesman which has a salesman as its protagonist, this question must be asked. Arthur Miller could certainly have made it perfectly clear to us what Willy Loman was selling, but he chose not to do that. The obvious conclusion is that if the reader does not know, it probably does not matter.
We do know that Loman carries "two large sample cases" with him on the road, that what he sells is part of a line of products (he mentions he has a meeting "to show the line" to a company), the products are sold by the gross (he mentions "two hundred gross" in one order), and he works for the Wagner Company. That is not much to go on if one were to make an educated guess about what Loman sells.
The fact that we do not know what Loman spends his life selling is fitting, because Loman does not believe that what he has spent his life doing matters anymore. It does not. He has always found his worth in his accomplishments (success as a salesman), so when he is no longer successful at work (not to mention the mess he has made of his family relationships) he can find no reason to live.
What Willy Loman sells does not matter because what Willy Loman does does not matter--at least not enough to inspire him to keep on living.
If a writer of prose knows enough of what he is writing about he may omit things that he knows and the reader, if the writer is writing truly enough, will have a feeling of those things as strongly as though the writer had stated them. The dignity of movement of an ice-berg is due to only one-eighth of it being above water. A writer who omits things because he does not know them only makes hollow places in his writing.
-Ernest Hemingway, Death in the Afternoon
It may be a weakness in Death of a Salesman that the viewer is never informed about what kind of merchandise Willy Loman is selling. Arthur Miller may have "omitted" this detail because he didn't know enough about traveling salesmen and about marketing. As a result there seems to be "hollow places" in his writing. Miller provides very scanty information about what Willy actually does on his trips to New England. We don't know whether he went to stores or to offices, or both. We don't know whether he made appointments by telephone or just dropped in on buyers. And we don't know these things because Arthur Miller probably did not know anything about such business dealings either. Miller wanted his main character to be a salesman because plays always consist of a lot of talking. Dialogue is practically everything in a play, and Miller wanted to write about an insignificant little working man. A salesman makes a good character because he is used to doing a lot of talking; yet he is usually a lower-middle-class type with a limited education.
David Mamet's excellent play Glengarry Glen Ross features four salesmen. We know that they sell land in distant states, but the details are vague because Mamet does not seem to know much about selling that kind of real estate.