Pros
By far the biggest pro is the stock price: stock tripled while I was there. Also, at Amazon I had the chance to to work with some of the most dedicated and hardest working individuals in my life. This can be good or bad, but I am putting in the Pros: everyone I worked with at Amazon is very smart. If you work incredibly long hours after a few years you may get promoted. And if the stock price is moving in your favor, this could be a big chunk of change in your pocket.
Kontras
I also had the opportunity to work with some of the meanest, most selfish, most back stabbing individuals in my life. Lots of stress and turnover. I am putting the following on the cons (for some people it may be a pro) - Amazon is a high performance, high energy company. This means lots of long hours; once you are not performing you will be out the door in 3-4 months no questions asked. This applies to new hires as well as "tenured" employees. I am also putting this in the cons (for some people it may be a pro) - as you stay in the job and as you are performing, your job will get progressively harder and harder and your responsibilities will progressively increase. But you not get any pay increase or bonus for years to come.