S.D. Codified Laws § 37-33-3
For the purposes of §§ 37-33-1 to 37-33-11, inclusive, the term, pyramid promotional scheme, means any plan or operation by which a person gives consideration for the opportunity to receive compensation that is derived primarily from the introduction of other persons into the plan or operation rather than from the sale and consumption of goods, services, or intangible property by a participant or other persons introduced into the plan or operation. The term includes any plan or operation under which the number of persons who may participate is limited either expressly or by the application of conditions affecting the eligibility of a person to receive compensation under the plan or operation, or any plan or operation under which a person, on giving any consideration, obtains any goods, services, or intangible property in addition to the right to receive compensation.
SDCL 37-33-3