The compensation paid a real estate agent or broker is called commission or brokerage. He is not paid a salary, for if he receives a salary from his employer he is a salesman, not a broker. The amount of commission or brokerage is commensurate with the size of the transaction, that is, the amount of money involved. There is usually a rate of commission agreed upon or fixed by the custom of the business. Each transaction is paid for separately, so that the earnings of the broker are dependent upon his success in bringing about transactions.