A multiple listing service is a facility of cooperation of agents and appraisers, operating through an intermediary which does not itself act as an agent or appraiser, through which agents establish express or implied legal relationships with respect to listed properties, or which may be used by agents and appraisers, pursuant to the rules of the service, to prepare market evaluations and appraisals of real property. If an open listing is placed in the multiple listing service, the total compensation that the owner is to pay shall go to the selling agent who procures an enforceable offer from a ready, able, and willing buyer on the terms accepted by the owner. An open listing need specify no compensation to the selling agent, but may state that the compensation is to be negotiated between the selling agent and the owner.