Among the most visited websites around the world, Facebook had roughly 152 million unique U.S. visitors in March 2012— or, more than two out of three Americans who were active online visited Facebook. This rate is even less than in other markets, including Brazil, New Zealand and Italy, underscoring Facebook’s transcendence of borders around the world - and on the world wide web.

Since its founding in 2004, the social network has passed many milestones as it skyrocketed from a few million U.S. users to millions more around the world. Looking back at Nielsen data from over the last eight years, here are some of the key moments in Facebook’s story:

• In January 2009 Facebook passed Myspace to become the top social network/blog site for the first time, a position it’s held in the U.S. ever since.
• Between 2005 and 2009 Facebook doubled its traffic each year in the U.S., surpassing 10 million uniques for the first time in November 2006 (11.6M).
• Facebook connected friends around the globe quickly: reaching 10 million unique UK visitors by April 2008. In 2009, the French, Spaniards and Germans followed suit, with 10 million visitors apiece in January, May and November, respectively.
• As recently as August 2011, Facebook overtook Orkut as the top social networking site in Brazil; it has continued to grow its audience since then.

Facebook continues to grow around the world, with consumers in each market finding unique uses for social media sites. While Facebook is the top social network globally, many netizens visit multiple social media sites; in Japan blog sites are more popular in the social media category (Facebook is ranked 5th), and in Brazil sites like Tumblr and Google+ are growing quickly as well. Currently Facebook is the top Social Networking & Blogs site in eleven of the following 12 markets: