As of January 2013, Linked In in more than 200 countries and regions have more than 200 million users.
Pinterest allows users to create and manage theme collection, such as events, interests and hobbies.
Since its introduction, Twitter has become the Internet's top ten most commonly used sites, and is known as "Internet SMS."3, Linked In Linked In is a professional social networking site in the United States.
Linked In was created in December 2002 and was launched in Monica, California on May 5, 2003, and Linked In is mainly used for professional networks.
Pinterest allows users to save images and sort them.
Popular categories include travel, cars, food, movies, humor, home design, sports, fashion and art. Now, Google is the world's second largest social networking site, Google in January 2013 beyond Twitter.