I think facebook is a perfect example of what happens when businesses are created "by accident", where a product is created first then a business model is grafted on afterwards. As the article mentions the needs of the users are in conflict with those of advertisers and it's a problem.

An increase in value for advertisers means a decrease in value for users. Users want privacy, advertisers want everything in the open. Facebook in an attempt to sustain growth has effectively forced users to accept people within their networks that they aren't really close to and this makes users less comfortable in their own space.

Facebook is at a critical juncture and its future depends on how it manages the problems they are facing now because the house of cards can come tumbling down at any moment. What they have going for it though is that there isn't really any clear alternative at the moment that users can turn to. What clear though is that people do want an alternative but till then I suspect most will bear with it till the alternative comes to their rescue.