Zynga Sets Aside a Huge Pile of Stock for Employees
 

What is the best way to keep an employee from leaving a sinking ship? The best way is to make them part of the ship, naturally. That must be Zynga's strategy for preventing the flow of employees out the door in the future. Zynga has been experiencing a downside since going public late last year. However, these grants and options will undoubtedly be restricted in order to prevent employees from exercising them any time soon. Typically, stock option grants have a four-year vesting period, with zero shares vesting during the first 12 months.

http://www.hardocp.com/news/2012/08/...for_employees/