Sheryl Sandberg is an American technology executive, activist, and author. She is the COO of Facebook and founder of the Lean In Foundation. She co-authored Lean In: Women, Work, and the Will to Lead, which became a bestseller on several lists. She was named one of the 100 most influential people in the world by Time Magazine. Sandberg is reported to be worth over $1 billion, due to her stock holdings in Facebook and other companies.