Facebook is a social media phenomenon and introduced the concept of "social utility". It was founded by Mark Zuckerberg in 2004 and is currently led by him as CEO. Some key investors include Peter Thiel, Accel Partners, Greylock, and Meritech Capital Partners. Facebook has over 1 billion monthly active users and generates revenue through advertisements and other services. Its popularity stems from allowing users to connect and share with friends and family.