Did you know that an additional 0.1 second in the time it takes a web page to load can lead to a 1% decline in customer activity? Neither did I. But Amazon does. In fact, the company has about 500 metrics that it tracks every day, the majority of them relating to the customer experience. Many companies pride themselves on moving from quarterly to monthly customer feedback sessions. Amazon measures a feedback loop in seconds — or in tenths of a second.