Final answer:
The third party to a listing contract is a customer; they are not bound by the contract unlike the principal and the real estate broker, who have a direct contractual relationship.
Step-by-step explanation:
The third party to a listing contract is typically a customer. A listing contract is an agreement between a real estate owner (principal) and a real estate broker, where the broker is authorized to act as an agent in the sale of the real estate property. In this contract, the principal and the real estate broker are the two primary parties involved.
A customer is generally considered to be a third party because they are not bound by the listing contract, but rather they are potential buyers or clients who the broker may bring into the transaction. However, they do not have the same contractual obligations or agency relationship with the broker as the principal does. The broker represents the seller and has a fiduciary duty to them, but the customer is served by the broker without such a duty.