Some people claim that Facebook will be replaced by some other social network such as Google+. I think that the real Facebook killer will be the Lack of Reciprocity:

If you are constantly posting about your personal life, you will eventually discover that your hundreds of “friends” know everything about you, but most of them don’t want to tell you about their lives.

This is my classification of Facebook users, according to the way they use it and the kind of information they publish: 

• Naïve Users: Are very active users, publishing lots of personal information and family pictures. They will let you know everything about their lives: In which restaurants they eat, what clubs they frequent, where they are planning their vacations. They have many albums with lots of pictures, some of them very personal. They also frequently comment and like the posts of others.
• The Jokers: They like to post statuses that they think are very funny and/or smart, such as: “How are turkeys called in Turkey?” They will never publish anything personal. If they upload a photo, it will probably be something bizarre they saw in the street. They don’t comment or like the statuses of others, but it is very important for them to have as many people as possible liking their own posts.
• The Linkers: They provide lots of links to things they think are interesting and should be shared, like videos on YouTube, TED talks and news articles in digital journals. They also like to be the first to share some breaking news like “Michael Jackson is dead!” The Linkers never post any kind of personal information.
• The Gamers: They spend most of their time playing games at Facebook, and their many posts are all notifications of the kind “Nancy has found a lost cow in his farm!” The Gamers don’t post personal information, but they will frequently invite you to play with them.
• The Fans: They use Facebook very actively to follow everything their friends are publishing. They frequently comment and like other people’s posts, but never write about themselves. They make a true effort to be nice and friendly, but do not share about their own lives.
• The Wishers: They only use Facebook to wish a “Happy Birthday” to their friends. They connect every day, check who has a birthday, and then post a congratulation message on his/her wall. If there are many such friends, they use “copy-and-paste”. The Wishers rarely write anything on their own wall.
• The Scanners: They use Facebook to always keep up-to-date about what is happening to his many contacts. They are very interested in other people’s lives, so they read every status and see every picture. If there is not enough activity in the News Feed, the Scanners will start checking who the friends of their friends are. As the name suggests, they never write anything, so they cause you the impression they are not using Facebook. But they are, and a lot!

It is obvious from this classification that the only people publishing any personal information are Naïve Users. Moreover, people using Facebook to read their friends’ posts are interested mostly in the personal information provided by the Naïve Users. The Jokers’ jokes, Linkers’ links and Gamers’ notifications are different types of garbage that only pollute the News Feed. There is nothing really “social” about them, so they do not contribute much in a social network.

I believe that eventually the Naïve Users will understand that they are sharing too much personal information with too many people. They will discover that details of their lives became public domain, while the people consuming this information, their “friends”, do not really reciprocate. Then I doubt they will continue sharing that much.

At the moment that Facebook will lack the personal information provided by the Naïve Users, its social aspect will be lost, and this will greatly affect the motivation of all other types of users.

Technology can provide us new tools to communicate, but it cannot change the inherent defects in human nature.