Pros
I love coming to work every day - I feel supported by my team and have built some very genuine friendships with my colleagues. The caliber of personnel who works here, at least in the Seattle office, is better than any place I've worked. The flexible work environment is my favorite perk - my time is not micro-managed, but instead I'm given the freedom to get my work done in the time/place that is most efficient for my personal work style and for that I feel inherently accountable to the company to do my best work. It's a win-win. There is so much creative freedom to plan and kickstart new initiatives, events, etc. Have a great idea? There will guaranteed be other people to get excited with you and make it work. I've been here for two years, and can honestly say that I plan to make it at least to my five-year mark. BTW, you get a three-week paid sabbatical at five years! Already planning for it.
Cons
Fast-paced - I happen to love the fast pace, but it can be overwhelming if it's not not your thing. If you're not amenable to constantly changing deadlines and multi-tasking, this probably isn't the right fit for you. IT - they seem stingy with the hardware and it feels like a constant battle with them to get the support we need to be efficient in our jobs.