These online grocery services provide virtual stores through which the electronic visitor navigates, as if pushing a shopping cart in a traditional grocer. The user clicks on items to purchase, which are placed in the user’s cart. When complete, the user is “checked out,” specifying a delivery date and time (paying a premium for narrower windows of delivery time precision, such as from 1 to 1:30 compared to 1 to 4 p.m.). Users pay annual dues and delivery costs proportionate to each shopping bill.