Pros
It's truly a hands-on experience. Guest speakers from all types of industries come once a week. It's a start up company and they really value your opinion which is nice as an intern. You meet really, really great people. You work during the day but events are planned to be able to explore Los Angeles with your fellow interns. It is unpaid, but you know that when you agree to it. I had an amazing summer last summer.
Cons
It is a start up so they do not have many resources yet. You really need to be on top of yourself sometimes and work with your team to come up with ideas so that you are not wasting time just sitting there. There is a lot of freedom and thus this can be taken as not doing any work. It also depends a lot on the group you are in - Multimedia was fun and I learned. I would probably stay away from Social Media though because there's not much to do.