Main Entry: re·fer·ral
Pronunciation: \ri-ˈfər-əl\Function: noun
Date: 1927
1 : the act, action, or an instance of referring <gave the patient a referral to a specialist>
2 : one that is referred
(businessdictionary.com)
REFERRAL SELLING: Acquiring new customers who are suggested or referred to by existing customers. Referral selling is the basis of all direct selling such as network marketing.