Pros
It's pretty cool to work for a company where you can call yourself a customer and an owner. Amazon truly does think about the customer first, and all business decisions are generally made with the customer in mind. It's nice to have access to some of the creators of one of the best (if not the best) product recommendation tools. Amazon definitely has the power of a large corporate company (along with all of the red tape that goes with that), but that strong corporate brand name alone helps secure meetings with potential partners. The Amazon discount is small, but I suppose it's good that you get one!
Cons
Amazon is a very top-down focused company. Upper management scrutinizes and edits every small detail in a presentation or proposal, and lots of unnecessary time is spent making an unimportant item perfect. The company talks a lot about being able to think of an idea, develop it and implement on the site quickly, but there are layers upon layers of approval needed. Management definitely works a LOT of hours, and expects all team members to do the same, so the work-life balance is fairly nonexistent. Employees are expected to be available at pretty much all times, but then they won't pay for a Blackberry or email-enabled phone.