Who Killed Wal-Mart's Business Model?

For more than three decades, Wal-Mart ruled the US retailing industry. Its large stores and everyday low prices were too much for smaller neighborhood stores and supermarkets that ended belly-up shortly after Wal-Mart invaded their turf. That’s how Wal-Mart ended with close to a half-trillion in sales, dwarfing the economies of smaller countries. But in recent years, Wal-Mart’s business model seems to have headed for the graveyard, and the company has closed scores of stores. Apparently, wha...