"Narcissists are characterized by a grandiose self-view, an excessive preoccupation with themselves, and an instrumental use of social relationships. In other words, we may recognize narcissists by their fixation with their own accomplishments, their inability to admit to personal flaws, and the inordinate amount of time they spend talking about themselves. But often, we fail to "spot the narcissist" because they can be extremely charming, at least initially. We are often mesmerized by their animated anecdotes starring—you guessed it—themselves, and their engaging manner. Unfortunately, however, social relationships with narcissists tend to be one-sided: Narcissists are uninterested in other people, and view them simply as a supply of attention, affirmation, and validation. Indeed, deep down narcissists are plagued by insecurities and self-doubt, and desperately crave positive social feedback in order to quell these feelings.
Social networking sites in general and Facebook in particular have been described as havens for narcissists. People think such platforms are ideally suited to narcissists because, by definition, they invite people to discuss themselves, no matter how trivial the details of their everyday lives may be, and to attract attention from social networks in the form of "likes" and comments."