Alicia Eler shares a quote:
"One of those things that distinguishes Facebook, is there is no obvious decay mechanism for friendships," says Dr. Sam Gosling, a professor of psychology at the University of Texas at Austin. "We meet many people everyday. Some of the people we meet become close friends, others we never see again, others acquaintances. In normal life, if you don't maintain a friendship it goes away. Facebook leaves a concrete link to that person."