Regarding the development of Facebook from an theoretical point of view it is not so surprising that it is so successful.
The main idea of an e-comunity is to communicate. So it is possible to develop four steps to make a e-comunity successful:
1) Member acquisition:
Get more community members. There is not so much mentioned in beginning of faebook’s development. But later functions like “Freundefinder” (in English I think it’s “friends finder”) tend to this step.
2) Member loyalty:
The objective of this step is to advance the communication of the members and thereby increase their loyalty. Here as it’t mentioned in the article is the news function a great invention. If someone publishes any information every friend noticed this and is able to answer.
These first two steps are part of the attendance advancement. The other 2 parts are revenue orientation:
3) fringe benefit
creating of user-profiles and selling directed marketing campaigns.
4) essential benefit
selling own products or charing fees
But regarding its effect to the society I think this depends absolutely on the use of a social network. On the one hand Facebook is a social network, the things which are published there are private and the communication is like seeing each other. You are able to get a lot of information about your “friends”, but on the other hand I also think it is not the same approximately like meeting each other and see someone in real life. Furthermore you also have to distinct between real friends and Facebook “friends”. I think it is possible using new media to stay in contact with friends but in the end you’ve got different lives in the real world.
Regarding the privacy it also is not astonishing that Mark Zuckerberg is not interested in this topic if he follows the described method for making a e-comunity successful.