Soon railroads, department stores and other businesses adopted Hollerith punch cards to track customers and cargoes.

Other resorts, such as Vail, use bar codes instead of tickets to track customers, who physically show their cards when they pass through the lift line.

Avon was chosen, in part, by using ZIP code data from its stores' sales receipts to track long-distance customers like the Campbells.

Courier Companies need a program to track customers that request a delivery, details about the package, and who will be delivering the package to the recipient.

That innovation would, Netscape argued, make it easier for servers to track customers.

The omni-channel consumer wants to use all channels simultaneously, and retailers using an omni-channel approach will track customers across all channels, not just one or two.

Some shopping centres have tracked customers through mobile phone signals.

It uses CRM to track customers in real time and runs a web-based patient database.

QFC uses a preferred customer card to track customers and offer discounts.

"Neverlost does not have the technological capabilities to transmit information, so it's physically impossible for us to track customers."