Pros
Amazon is a great place to work if you want to work hard, get experience, and network with lots of other people doing all sorts of jobs you never thought could exist. The benefits package is outstanding, and the salary is very competitive. There are a lot of opportunities for advancement--as long as you're willing to work hard, learn, and take feedback. The focus really is on the customer, and it's really nice to work for a company that actually practices what it preaches--from the top down *and* from the bottom up. Everyone is very respectful of one another, and disagreement is totally acceptable. It's a very open environment, and it feels like a flat management system even if it isn't.
Kontras
There's a bit of travel involved in some positions. There are some disconnects between departments, so you don't always know what's going on in another part of the business. That's not necessarily a bad thing, but it can be in certain circumstances. Occasionally a decision will be made that doesn't make a ton of sense, but that's true in any business environment, particularly in an environment that's so innovative and eager to stretch the bounds of what can and can't be done. There are also lots and lots of meetings... I've never worked at a place that valued meetings so much!