Pros
It's a lean team with plenty of room to take on new roles and learn a ton. With such a small team, you have plenty of space to explore potential sales/opportunities for the company and make an impact while working directly with the C-suite.
Cons
With such a small team, many processes have yet to be fully built out to run efficiently. There's so much that is being built as they fly which can be frustrating if you come from a structured corporate environment. If you're not able to seek out the answer, you'll have a tough time waiting for help.