Supermarket
Until the 20th century, grocery stores were small.  The owner, called a shopkeeper, would ask the customer what he or she would like to buy.  The shopkeeper would then get the items, bring it to the customer, and put them in bags which the customer would take with them.  He would then calculate how much the customer has to pay, and take the money from the customer.  The customer then took the bags of items out of the store by him/herself.