Zappos CEO Tony Hsieh's executive assistant — or "Time Ninja" — organizes his life. Liz Gregerson spends her days scheduling all Hsieh's daily activities — from meals to meetings to events.

Zappos CEO Tony Hsieh speaks at the company's All Hands employee event at the Smith Center for the Performing Arts in Las Vegas on Aug. 9, 2012. (Las Vegas Review-Journal file) ...