A seller might say that it is too difficult to determine whether a buyer participated in the transaction when a business broker is involved. However, the general purpose of an exclusivity agreement is to protect the broker from collaboration with a seller who breaks the agreement as soon as the seller meets with the buyer, eliminating the need to pay the broker for his services. The initial exclusivity clause between Apple and AT&T is rumored to last five years, but the exceptions and “out” clauses allowed Apple to start selling through other carriers a few years after the release of the first iPhone. The wording and execution of the clause with AT&T also helped Apple create a model for agreements in other countries where AT&T did not provide a service. .