Facebook has become the world's most popular social networking site with over 550 million active users, 50 million more than the population of China. It has strengths like keeping personal and public content separate, suggested friends, groups, comments, and messages. However, it also faces risks, as it relies on advertisements for over 80% of revenue but revenue growth depends on user growth, and it struggles to monetize mobile users. Facebook also faces privacy issues as users are frustrated by frequent changes to privacy settings. Privacy restrictions could limit Facebook's ability to offer personal marketing opportunities to companies.