I think that the main factor is the news feed. Due to human nature, we will always long to feel wanted or included in a group. With the mass amount of friends one has on Facebook, even if whatever is on the news feed is uninteresting, it feels as if the people featured on the news feed are speaking directly to you. If somebody has posted a link from YouTube that ended up on the news feed you could watch it, and then click a related video, and then another, and suddenly an hour has passed by.
In addition to the ever-so-addicting news feed, there are those applications that can keep a person occupied for a long time, depending on the application. Perhaps you have decided to see why Farmville is so popular, or want to play with an image on Picnik; the possibilities with an application is endless. Suddenly, you find yourself committed to a game that you were “just trying out” and you can’t leave it because of a silly time limit inside the game.
Assume you have added a classmate on Facebook; you know that your classmate is working on the same assignment as you, and decide that even though you do not really talk to he or she that often, they added you on Facebook so you’re entitled to the right to chat with them, right? As soon as you send your greeting, you have to continue the conversation to avoid being rude and logging off. Even when you try and continue working on your assignment, you constantly hear the “blip” sound that notifies you of a new message, thus losing your train of thought replying to the message.
Without these features, Facebook would be much less appealing and thus less of a distraction. However, Facebook is also an effective way to keep in touch with far away friends and relatives. My only advice to those who can’t seem to pry themselves away from Facebook is I find that closing my web browser when I need to get work done helps, although sometimes I subconsciously open it again, to check none other than Facebook!