Pros
You can learn a lot about SEO here. You can learn about how startups fail. You can learn about people management and what works well, what doesn't work well. You'll probably meet some cool people. You can play ping-pong as many times a day as you want, as long as you hit your numbers.
Cons
The senior management is constantly changing production workflow, employees' job titles and procedures. They give very little training when new versions of the software roll out, and they don't seek users' input on platform development. The CEOs value hold little regard for individual growth, job satisfaction, professional conduct. This company is very good at creating a front-facing image that looks great on paper, but behind the scenes they fail to meet deadlines and are always scrambling to keep their clients. The morale was always low, and as a mid-level manager, I was caught between the senior managers who wanted me to target people to fire - and my team, who wanted to be recognized and fairly paid for their hard work. It was a horrible place to work, but a great place to learn and grow as a human being.