This is a real weak spot for companies like Google and Amazon, which have very little experience delivering quality tech support. Rackspace is playing catch up on the technical side, but they really understand support. It goes a long way.
Some people may see "Fanatical Support" and cringe at it as marketing: it's really not. It's a company core value, and baked into the DNA of every person in the company from HR, to IT, support, engineering - customers, developers, etc are not just revenue - they're our family and friends.
Fanatical support is what makes Rackspace, well - Rackspace.
That's really reminiscent of Zappos. I don't know how their service first attitude was taken at first, but I think over the years we've accepted it as a genuine thing.
Racker here, joined about five years ago. Spent some of that time in direct support roles and one of the things that we did was take a trip to Zappos, participate in their culture program. Routinely we would engage with other companies who we believed to be providing great service and find if there were ideas we could apply to our own product. Fanatical Support is home grown, but we definitely look to others in the industry who are doing it right.