An online service that matches prospective clients with potential lawyers based on the appropriate geographic and practice areas, makes representations about the qualifications of its member lawyers, and provides a monetary satisfaction guarantee, is a “lawyer referral service” within the meaning of ER 7.2(b). Unless the service is a non-profit service or is approved by an appropriate regulatory authority, Arizona attorneys may not pay a fee to participate. See Arizona Opinion 06-06 (September 2006).