Pros
Learned everything I know about Paid Search as a Media Analyst and quickly got promoted. Learned from smart, passionate people who cared about doing a good job. Most people are friends outside of work, so moving to a new city, it's nice to have those type of co-workers. Was able to guide my own career and always felt comfortable asking questions and bringing up issues to management. Young company, lots of opportunity to launch your career, as long as you take control over it. People who are driven, work hard, and take notes will thrive here. People who wait around to be taught and not vocal about what they want will hate it here.
Cons
Top talent constantly leaving the company and going to Google or another tech company who can pay more and offer benefits (not a bad thing for those leaving) but hard to continuing learning if you're one of the more senior people left. Pay is good for a recent college grad, but as you become more senior, you expect more compensation, but it can be like pulling teeth. Not because management doesn't want to give it to you, but because there is limited funding for it to come from. People get restless by 1.5 years and start looking elsewhere.