Pros
The product itself is very cool, and apparently needed among college students. My co-workers were all very talented and dedicated, senior management put a big emphasis on holding brainstorming meetings to help solve problems. A startup environment is a great place for people to express themselves and be creative, any new ideas for features or improvements were always considered and usually also implemented if relevant. The work was challenging and all of the workers got a chance to work on lots of different projects so there's never a dull moment, you're always stimulated.
Cons
As the company grows there should be more presence of an HR department. The time difference between the tel aviv and sf offices makes communication somewhat challenging, and sometimes there's a need to work in the small hours of the night.