Pros
There are some very nice people here, and a decent handful who are trying hard to improve the office culture.
Cons
Almost everything else. Epsilon is run by the parent company, Alliance Data, and feels less like an agency and more like a column in a spreadsheet. The emphasis is always on the bottom line (which is, naturally, the necessity of running a business) in a way that can cause work/life balance to suffer. No system for comp time if you wind up putting in late night or weekend work, and you will put in late night or weekend work, that's a given. Rules are imbalanced or unfair across the office - working from home is discouraged in some departments, yet other departments (and the senior management's favorites) seem to barely log time at the office. Despite achieving Fortune 500 status, being offered a significant raise or bonus is a rarity. And as another review already mentioned, turnover at anything other than the senior level is very high, which should be a pretty big red flag.