Pros
Opportunity to affect culture, and your friends & family every day. The scale we build for is incredible. Where else do 50 M people play every day on what you build? Responsibility & accountability is everywhere - if you want it, you can have it. Opportunity to build on a world stage and do things that haven't been done before - every day. Insanely awesome perks - gym, incredible food, dogs everywhere, mobile culture, happy hours, quarterly meetings. Plenty of access to top management. You're not building your resume - you just want to be a part of something unique and meaningful. You like solving problems and doing something that's never been done before. You're comfortable defining and disrupting industries not walking in other brand's footsteps. You like to move fast and see results quickly.
Cons
Start-ups are for people that like accountability and responsibility. We have a high bar, a lot is expected of people at every level - you have to be comfortable with working hard and showing results often. Zynga moves really really fast. We have to stay ahead of what consumers want and where the market is going, we don't have time to do something next week or next month. Because we're doing something different, hours aren't always predictable. Prioritization can be tough - you can't get to everything so you have to chop out what doesn't matter. People need to see what something was a good idea, be ready to show metrics-driven results after you accomplish something. This is not a laid back, in-house job.