Pros
I interned here for a summer through my school's internship program and I absolutely loved it. I wasn't getting anyone coffee or booking meetings. I was gaining real, valuable experience at a social media marketing agency. I got to contribute to real campaigns and I had a lot of fun while there!
The people there are cool as well. Company culture is great. Every one is friendly and laid-back, and there's even "happy hour Fridays". The CEO asked me what kind of beer I liked and the next Friday the office fridge was stocked with my favorite brand.
They also made sure their employees were constantly learning, and would have weekly company meetings where someone would come in to speak about an emerging technology or something new in the social media space.
This is a great place to intern and I'm sure an even better place to work!
Cons
As far as interning goes, it really depends on who you're working under. I got to work under the coolest guy ever and worked on things that I found really interesting. My friend who was also interning there at the same time as me was stuck pinning things to a client's Pinterest account all day, which I can't imagine was a great learning experience.