Collegial environment, very little ego among employees, everyone is willing to work hard and help out.
If you work consistently you will be given more responsibility and there is a lot of room for creativity within roles.
Cons
The company is (as of Fall 2012) ~40 people split between four offices so there is definitely a communication gap. The media-buying audience is very entrenched and sales take a great deal of work. The product(s) are great but I'm worried about the lack of R&D in sellable media options.