Pros
Shopzilla has great people who are incredibly smart and driven. The downside to working with people like this is that they will hold you to the same standards. This is not a place where you can phone it in and expect not to be called out on it. My boss was always straight-forward about her expectations and kept a constant feedback loop open on my performance. I always knew where I stood, how to improve and could always go to her for guidance. There have been changes over the last year as the company has matured that have upped the intensity. There's still free lunch, great company events, casual dress code and interesting projects. This is not a place that is stagnant - there is always something new coming down the pipe.
Cons
There is some outsourcing going on which can be frustrating. Although it's a necessary evil to stay competitive, it can be disheartening to the onsite engineers and hard on those who need to provide support to those offsite teams.