Real product, real users, real ownership - anything you build has immediate impact
Strong focus on teamwork and individual development
High emphasis on continuous improvement as a company (let's see how we can make it better)
You have the opportunity to broaden your knowledge in all fields, not only your profession
Cons
Changing priorities is a frequent characteristic of startups. SSP is no exception
Sometimes gaining/keeping customers has a price (extra work)
A very laid-back, team focused and self-improvement focused atmosphere. The right amount of challenges and butt-kicking when you need it, but not so much that it grinds you down. A very agile and quick moving company culture, but also a constant focus on code quality. Small enough to have a real impact on the whole technical architecture.
Cons
Makes me feel like a total outsider in my own country: nobody seems to like their jobs this much. There isn't much of a "ladder" to climb: endless room for improvement, but not in job position.