The unfriending trend could spell trouble for Facebook's business model:
In gross terms, 158 million people were unfriended in 2009, and more than a half a billion in 2011. … Experts say that the fewer friends a person has, the harder it is for Facebook to interpret the world the subscriber comes from. In turn, the less information Facebook has, the less they can charge for advertisements on the subscriber’s page.
The above chart is from a recent Pew report (pdf) that found 18% of social networking site users have decided to block, unfriend or hide someone because of their politics or posting activities. More on the rise and fall of online empires here.
The Dish 