This is also done for profit with luggage carts at many airports, where companies like Smarte Carte charge two or more dollars (or equivalent) for rental, and return a small token reward of a quarter (25 cents) for returning carts to the other end of any dispenser machine.
In the United States, most shopping carts are made of metal or plastic and designed to nest within each other in a line to facilitate moving many at one time, and to save on storage space.
Often there is the problem of theft of shopping carts; for example, shopping carts are often used by urban homeless people to carry their belongings. One of the solutions is a system of sensors around the parking lot which block a wheel. Sometimes shopping carts are physically prevented from even leaving the shop, but that is mainly a solution if few customers come by car. Retailers report more than 800 million dollars of missing carts in the U.S. alone each year.
An alternative for the shopping cart is a small handheld shopping basket. A customer can often choose between a cart and a basket, and may prefer a basket if the amount of merchandise is small. Small shops often supply only baskets, where large carts would be impractical.
See also: moving sidewalk
Using the term metaphorically, an e-shopping cart (electronic shopping cart) is software which allows customers shopping on a website to accept product orders for multiple products from the website. This software automatically calculates and totals orders for customers and indicates the total price including post and packing.
Some setup must be done in the HTML code of the website, and the shopping cart software must be installed on the server which hosts the site or on the secure server which accepts sensitive ordering information.
See also: electronic commerce