It'll tell you a lot about how people are trying to cope with the economy, says Bill Simon, CEO of Wal-Mart's U.S. business. From the WSJ:
"It's real interesting to watch. About 11 p.m., customers start to come in and shop, fill their grocery basket with basic items, baby formula, milk, bread, eggs, and continue to shop and mill about the store until midnight, when...government electronic benefits cards get activated and then the checkout starts. "The only reason somebody gets out in the middle of the night and buys baby formula is that they need it," Mr. Simon said. "We are open 24 hours.... If you are there at midnight, you are there for a reason."