A neurology group practice recently analyzed its level of patient referrals and referral sources. This analysis showed that 60% of all referrals came from 35% of all the physicians who referred to the group. The remaining referrals came from the other 65% of the referral physicians. In examining this referral pattern, it was also revealed that 20% of all the primary care physicians in the group's primary service area had never sent a patient to the group for diagnosis or treatment. As the practice manager of the group, you have been asked by the physicians to develop a marketing strategy to deal with this information.