S.D. Codified Laws § 54-11-5
For the purpose of this chapter, "revolving charge account" shall mean an arrangement prescribing terms of transactions which may be made thereunder from time to time pursuant to which a retail seller or person who offers and provides any services gives to a purchaser or user of services the privilege of using a credit card or other means of credit confirmation or identification primarily for the purpose of purchasing consumer goods or services, as that term is hereafter defined, from any person, which may include the retail seller or provider of services, and under which an interest charge may be periodically imposed.
For the purpose of §§ 54-11-5 to 54-11-8, inclusive, "consumer goods and services" mean all goods and services provided to the public by sellers or providers of personal services.
SDCL 54-11-5