There are around 200 stores and 60 operators across Germany. The walk-in format is widespread; these are supermarkets with often reduced retail space.
Customers usually scan the products themselves and pay at self-service checkouts. In other stores there is no checkout at all; the products are recorded by camera. Sunday is very valued by customers. Sales are as big as two to three working days combined, says Stephan Rüschen, professor of food retail at Baden-Württemberg Cooperative State University in Heilbronn.