Avantages
Working at Amazon is like attending the most cutting-edge technology and business school you can imagine. The hiring bar is extremely high, so everyone is extremely talented. Amazon VP's are some of the smartest people you will ever meet. The whole company moves so quickly that every day you are working on a new major initiative. The leadership principles are literally used everyday - people quote them in meetings, and the company only focuses on customers, never on competitors. It's quite remarkable. If you get an offer to work at Amazon, take it.
Inconvénients
I stayed for over 6 years which put me above 98% of other Amazonians (there's a tool called "oldfart" that compares your tenure to other employees). Most people only last 2-3 years for several reasons. First, the pace is relentless which at first is exhilarating but becomes downright fatiguing. Second, Amazon doesn't really care about you as a person - only as a productive cog in the machine. Third, the RSU award program is ok, but total comp is really only great if the stock is climbing 30% a year. Finally, everyone wants to hire an ex-Amazonian right now. When you combine these, Amazon becomes an amazing training ground, but not a great place to stay long-term.