Pros
Amazon doesn't want you to stay in a stagnant position, they want to help you advance your career Amazon provides many resources to further your education, even if it's not related to your job Amazon has great benefits including health/dental/vision insurance, life insurance, injury insurance, 401k, stock purchasing program, legal assistance, etc.
Cons
Because the company grows so fast and everything is constantly changing, it can be difficult to nail down some cohesion when it comes to policies and procedures. What you thought was the correct way to do something can quickly become outdated, so it takes getting used to. The divide between the IT departments and the Operations departments can be a little frustrating. You're constantly trying to fix broken things in a large warehouse, but I would hazard that this is not Amazon specific.