California Code, Business and Professions Code - BPC § 10167.2

(b)(1) The requirements of this article apply only to the provision of listings of residential real properties for tenancy by prepaid rental listing services.  Except if expressly provided otherwise in this article, the requirements of this article do not apply to any other goods or services sold by a prepaid rental listing service as long as the purchase of those goods or services is not required to obtain those listings, and as long as the purchase of those goods or services is not included in the same contract as the contract to provide those listings, and as long as the contract to provide those listings clearly specifies that the purchase of any other goods and services is optional, and as long as the price charged for any other goods and services is fair and reasonable.

(2) In an action alleging that the price charged for any other goods and services is not fair and reasonable, the burden shall be on the commissioner to demonstrate that the price charged unreasonably exceeds the fee customarily charged for the same or comparable goods or services in the community in which the prepaid rental listing service operates.  The fact that the price charged for goods or services exceeds the cost incurred by the prepaid rental listing service shall not render the price charged for the goods or services to be unfair or unreasonable, so long as the price charged does not unreasonably exceed the fee customarily charged for the same or comparable goods or services in the community in which the prepaid rental listing service operates.