Pros
If you're young and don't have a ton of experience or financial obligations, it's a decent place to get your feet wet or break into a new industry. Could be a good resume builder.. but be very careful before you sign any paperwork, don't let them make you sign a non-compete that keeps you from getting a decent job if you ever leave. Sometimes you get free food and drinks. Most of the mid-level people are super cool.
Cons
Be prepared to be overworked, underpaid and under appreciated and then told it's "start up life" ..even after you have continuously accepted an increasing workload with no additional compensation. The majority of the people working there are immature and inexperienced. Some people take their job title way too seriously and think they are better than others. Communication is seriously lacking, especially between HQ and remote markets.