This is an interesting piece from the Harvard Business Review on Zappos. Apparently, Zappos pays customer service reps $1,000 dollars to quit (if they don't like their job). 10% of employees take them up on that offer.
The interview details the hiring practices of Zappos. I found it to be an interesting piece which could be helpful in your endeavors. In a previous life, I had a ton of great people that we're on the front lines of helping corporate travelers. You either need to be massively operationally efficient or have fat margins to pull off this type of customer service experience. I don't know what Zappos' margins are but hiring passionate customer service reps that are enabled and empowered to make decisions is an incrediblely powerful retention tool. My guess is that Zappos has built in a bunch of operational efficiency around support increased support costs. A lot of businesses have used operational effiecny as an offensive strategy against their competitors. Southwest Airlines comes to mind. They used a specific service delivery strategy (point-to-point model versus the traditional hub and spoke model) to lower prices as well as developed a culture around having fun to really differentiate themselves in the market.