LinkedIn is is a business-oriented social networking service. Founded in December 2002 and launched on May 5, 2003, it is mainly used for professional networking. In 2006, LinkedIn increased to 20 million members. As of June 2013, LinkedIn reports more than 259 million acquired users in more than 200 countries and territories. Alpha Phi Delta is found on LinkedIn in at the National Fraternity's Central Office LinkedIn page and on it Alumni Network page.
Facebook is an online social networking service headquartered in Menlo Park, California. Its website was launched on February 4, 2004. After registering to use the site, users can create a user profile, add other users as "friends", exchange messages, post status updates and photos, share videos and receive notifications when others update their profiles. Additionally, users may join common-interest user groups, organized by workplace, school or college, or other characteristics, and categorize their friends into lists such as "People From Work" or "Close Friends". Facebook had over 1.3 billion active users as of June 2014. Alpha Phi Delta has a fan page at this link.