Vantaggi
The best reason to work at ESI is that you get to work with a highly passionate group of individuals. You really get the sense that everyone there loves interactive marketing and that the whole team is on a constant quest to push the envelope further. You can't possibly work there without some of this enthusiasm rubbing off on you - which is a good thing because it pushes you to hone your craft.
Svantaggi
As with many things in life, there were instances when I felt that the strength of ESI could also be a weakness. While it didn't happen often, there were a few times when all of that energy and passion seemed to worked against the cohesiveness of the unit. Even so, when things settled down and a consensus was reached one always walked away with a sense of the team's invincibility when it came to solving difficult SEO challenges.