It starts at the top
Zappos CEO Tony Hsieh states that if we're serious about building our brand then "customer service shouldn't be just a department. It should be the entire company." If they get the culture right, everything else will file into place.
Everyone hired has to go through two interviews, and there's really more stress put on being able to fit into the culture just as much as performance. In fact, if you treat the bus driver poorly on the shuttle ride from the airport, Zappos won't hire you.