The Office of the Inspector General (OIG) of the United States Department of Health and Human Services (HHS) has issued a favorable opinion to a dental supply company that an expansion of its points/reward system for dentists who are loyal customers to use when purchasing various dental supplies does not violate federal anti-kickback laws.  You can read the HHS OIG opinion here: HHS OIG Advisory Opinion on Dental Suppliers Customer Loyalty Program for Dentists.