Pros
I have worked here less than a year. This company is not for the lazy, faint of heart or unmotivated. You will work hard, make game-time decisions by yourself and get real results. You will get real life experience. No one is going to do your work for you, and you are expected to pull your weight. It's not kidding when it says it's a "fast-paced, growing company." That means you sometimes roll with the punches and learn. There are many young, fun, motivated individuals that work for C-4 which makes it a fun environment to work in.
Cons
You will work more than 40 hours a week. Welcome to marketing. But if you keep focused and get work done every day, it shouldn't get to be unmanageable. Sometimes you are expected to stay late, even after your work is done for the day, but not by management.