A.A. "service" is anything that helps us to reach a fellow sufferer. Much the way A.A. sponsors share their experience in recovery with their sponsees, a "service sponsor" can be defined as an alcoholic who, having made progress in recovery as well as participated in service, shares this experience with another alcoholic starting their own journey in service. Service sponsors are usually knowledgeable in A.A. history and principles and have a background in the service structure. For more information read page 25 of P-15, Questions and Answers on Sponsorship.