It is, but it's still in Vegas and it looks like the original CEO has pretty good control over the company. My friend had interview there back in college and they seems kinda over-obsessed with "culture fit". I mean when most companies talking about culture fit that basically equals to "we wanna hire nice people", but Zappos seems has really restricting rules on that part.
Anecdotally, I don't agree with the hypothesis that culture fit means they want to hire nice people. I've worked in a few places where people needed to be, for example, tough, tricky, bitchy, to survive.
I think part of the reason I got my job is because I euphemistically referred to "successfully implementing technical solutions in a complex political environment", and everybody knew exactly what I was talking about.