As Facebook prepares for its IPO, experts say the social network's fate is largely in the hands of Chief Operating Officer Sheryl Sandberg. Her business acumen and ability to build lucrative revenue streams will be the key to turning Facebook into a lasting, investor-friendly company, says "The Facebook Effect" author David Kirkpatrick. "It's a tall order to become a blue-chip company in a business that changes as fast as Facebook's does. ... If it's going to achieve it, Sheryl has to stay for a long time," Kirkpatrick says.