S.D. Codified Laws § 10-50B-6
For the purposes of §§ 10-50B-1 to 10-50B-10, inclusive, the term, units sold, means the number of individual cigarettes sold in the state by the applicable tobacco product manufacturer, whether directly or through a distributor, retailer, or similar intermediary or intermediaries, during the year in question, as measured by excise taxes collected by the state on packs bearing the excise tax stamp of the state, or on roll-your-own tobacco. The secretary of revenue shall promulgate, pursuant to chapter 1-26, such rules as are necessary to obtain information from any licensee, licensed under the authority of the Department of Revenue, to ascertain the amount of state excise tax paid on the cigarettes of such tobacco product manufacturer for each year. The Department of Revenue may provide information obtained pursuant to this section as is necessary for a tobacco product manufacturer to compute its escrow payment under § 10-50B-7.
SDCL 10-50B-6