The New York Times writes:
With 3,600 stores in the United States and roughly 100 million customers walking through the doors each week, Wal-Mart has access to information about a broad slice of America – from individual Social Security and driver’s license numbers to geographic proclivities for Mallomars, or lipsticks, or jugs of antifreeze. The data are gathered item by item at the checkout aisle, then recorded, mapped and updated by store, by state, by region.
By its own count, Wal-Mart has 460 terabytes of data stored on Teradata mainframes, made by NCR, at its Bentonville headquarters. To put that in perspective, the Internet has less than half as much data, according to experts.
Information about products, and often about customers, is most often obtained at checkout scanners. Wireless hand-held units, operated by clerks and managers, gather more inventory data. In most cases, such detail is stored for indefinite lengths of time. Sometimes it is divided into categories or mapped across computer models, and it is increasingly being used to answer discount retailing’s rabbinical questions, like how many cashiers are needed during certain hours at a particular store.
All of the data are precious to Wal-Mart. The information forms the basis of the sales meetings the company holds every Saturday, and it is shot across desktops throughout its headquarters and into the places where it does business around the world. Wal-Mart shares some information with its suppliers – a company like Kraft, for example, can tap into a private extranet, called Retail Link, to see how well its products are selling. But for the most part, Wal-Mart hoards its information obsessively.
Wal-Mart uses its mountain of data to push for greater efficiency at all levels of its operations, from the front of the store, where products are stocked based on expected demand, to the back, where details about a manufacturer’s punctuality, for example, are recorded for future use. The purpose is to protect Wal-Mart from a retailer’s twin nightmares: too much inventory, or not enough.
Eventually, some experts say, Wal-Mart will use its technology to institute what is called scan-based trading, in which manufacturers own each product until it is sold.
“Wal-Mart will never take those products onto its books,” said Bruce Hudson, a retail analyst at the Meta Group, an information technology consulting firm in Stamford, Conn. “If you think of the impact of shedding $50 billion of inventory, that is huge.”