Harvard political scientists designed a bogus social network in China and observed how it became blocked:
What they found was that the service providers and software firms provide a huge variety of choice in censorship methods, ranging from blocking certain keywords, to delaying publication on posts until they can be reviewed, to blocking certain users by IP address, to filtering out posts based on length. In other words, there isn’t a centralized set of guidelines banning any mention of Ai Weiwei, Tibet, or Tiananmen Square, companies are instituting their own guidelines in hopes of avoiding the government’s periodic crackdowns. As the MIT Technology Review put it, the experiment suggests that “China has created a kind of competitive market in censorship… Companies are free to run their censorship operations mostly as they wish, as long as they don’t allow the wrong kind of speech to flourish.”
Jeffery Wasserstrom adds:
[M]any know that Beijing uses a “Great Firewall” to try to keep the web free of things it dislikes. What fewer appreciate is how much energy the Chinese government puts into trying to flood the Internet with things it likes. People can earn small payments, on a post-by-post basis, for adding pro-government comments to sites. Bloggers mock this piece-rate system: those benefiting from it, they say, have joined the “Fifty-Cent Party” that props up the Communist Party.
The Dish 