Pros
The people I worked with were some of the best. After leaving the position, I'm still good friends with several of my co-workers. The position was also very flexible. We had the option to work remotely for 2-3 days/week which was also really nice. I think many people stay because of the good work/life balance and the friendly people.
Cons
They use an API when setting up and managing PPC campaigns for AdWords and Bing. The API is not as intuitive or user friendly as just going into AdWords or Bing. You also don't get as many options and features for optimization and reporting. The reporting was really bare-bones unless you took it upon yourself to customize your own reports. I also had upwards of 300 accounts I was managing. This makes it impossible to make connections with clients and also means you might not look at an account for an entire month unless there's an issue. This makes for a very reactive environment, instead of proactive. Not a good experience for the customer and causes a lot of undue stress for the analysts that are trying to juggle everything.