A lawful agreement by either the seller or the buyer for exclusive dealing in the kind of goods concerned imposes unless otherwise agreed an obligation by the seller to use best efforts to supply the goods and by the buyer to use best efforts to promote their sale.
"'[U]nder the covenant of good faith and fair dealing, a party [exercising discretion must] refrain from doing anything that will have the effect of frustrating the right of the other party to receive the fruits of the contract between them.'" This means that each party must "do nothing to destroy the rights of the other party to enjoy the fruits of the contract and  do everything that the contract presupposes they will do to accomplish its purpose." In addition, the obligation to act in good faith and deal fairly prohibits a party from terminating its contract (or otherwise exercising its discretion) to "recapture" an opportunity that it lost upon entering the contract. . . . [T]he obligation of good faith and fair dealing requires a party exercising discretion to do so in accordance with the "reasonable expectations" of the other party.