Want to avoid losing friends on Facebook?
A new study shed some light on how to make sure you keep your friend list healthy:
Respond to posts: If someone posts on your wall, reciprocate. The study found this to be the single most important factor in a successful Facebook friendship.
Cool it with the photos: Don't post embarrassing pictures of friends—and think twice before you post anything on a friend's wall about the crazy weekend you all had, since you never know who might see it ... and judge.
Wish acquaintances a happy birthday: The researchers found that people consider it more important that their casual acquaintances send Facebook birthday wishes than their close friends. That's because close friends can always call, text, or say it in person instead.
Don't get too familiar: If you're simply acquaintances with someone, don't try to use Facebook to chat with them or post on their wall (except on their birthday, of course), because that could be considered creepy.