Amazon trounces rivals in battle of the shopping 'bots'
Earlier this year, engineers at Wal-Mart Stores Inc (WMT.N) who track rivals' prices online got a rude surprise: the technology they were using to check Amazon.com several million times a day suddenly stopped working. Losing access to Amazon.com Inc's (AMZN.O) data was no small matter. Like most big retailers, Wal-Mart relies on computer programs that scan prices on competitors' websites so it can adjust its listings accordingly. A difference of even 50 cents can mean losing a sale.