Interesting how stores have reverted to the earlier days style where you handed the grocer your list and he got the items for you. You did not get the items till you paid.
!916, Piggly Wiggly, Memphis, Tennesee started the first self shopping experience.
Service Merchandise used to do that too. You shopped in their showroom or from a catalogue and wrote down product numbers of the things you wanted to buy. The clerk got your items from the back room and you paid before got them.