For banks and other retain establishments where the customer goes to a service desk (or joins a queue): the store is provisioned with seating in excess of the number of serving staff, with seating in pairs (one for the customer one for the service personnel) or groups (for families). Upon entering the store, a customer takes a seat and is added to an electronic queue (via automatic sensing or the push of a button). The service personel move to each customer in turn to address their needs. Obviously such a store would need to be larger than an existing equivalent, as a standing queuer takes up less space than a sitting queuer. But other than that, the service models are equivalent.
For stores where the customer collects items from shelves, the above model would need to be expanded upon to include a barcode reader at each seat, but it otherwise equivalent.