German to English Marketing Furniture / Household Appliances

This is in the context of food retailing. The glossary provides the revelation that SB refers to self service, but is that really what´s meant here? Unfortunately I don´t have much specific context, only the passing reference that follows. It´s an example of when a coupon is issued at the checkout counter.

"Kauf eines Artikels einer Warengruppe (z.B. SB-Käse)"