Facebook is the largest social networking service in the game today. As of September 2012, Facebook has over one billion active users, more than half of them using Facebook on a mobile device. Users must register before using the site, after which they may create a personal profile, add other users as friends, and exchange messages, including automatic notifications when they update their profile. Additionally, users may join common-interest user groups, organized by workplace, school or college, or other characteristics, and categorize their friends into lists. In April 2012, Facebook (NASDAQ: FB) acquired Instagram, the photo-sharing service and social network for approximately $1 billion in cash and stock. Definition in part from Wikipedia
Positive Points:
Self-identification -- fans choose to follow or like their favorite organizations, voluntarily identifying themselves as fans, in the same way that wearing a jersey or having a shopping club card identifies themselves as fans
Fan page administrators get a level of analytics -- number of fans added, comments, likes, visits -- through weekly reports [details about demographics, longer-term growth and engagement trends through the Insights feature]
Possible contest platform -- drive traffic to the Facebook or brand page, offering something more to those fans already engaged with your organization
Free to sign up and use
Largest social network by far with over 1 billion active users
Potential Pitfalls:
The immediacy Facebook raises the risk of posting something you come to regret
Behind every Facebook page is a human, and mistakes can happen
Individuals and organizations can find themselves in the crosshairs for posting something others view as 'questionable'
TMI syndrome - companies run the risk of employees sharing confidential information, trade secrets, intellectual property
Facebook's open nature -- you may be tagged in other's photos, posts and pages are linked to and preserved longer than anticipated
Concern by some over privacy issues -- Facebook is too large, has too much information, difficult/confusing to control privacy levels