Why The Great Firewall is Effective
The Great Firewall's success is primarily resultant from its non-confrontational way of blocking websites. The Great Firewall never explicitly tells you that its blocking a website or that you are trying to access prohibited information, it just induces an error in your web browser. This lessens the blow of censorship because no one can be sure if what they are trying to access is really prohibited or if it is just a problem with their computer or ISP.
Further, the Great Firewall strikes a delicate balance between not unduly restricting commerce and still restricting free speech. The firewall is easy enough to bypass with encrypted web traffic and virtual private networks so that any company that needs to securely communicate with the outside world can do so without censorship or fear of prying eyes. Additionally, the Firewall will not prevent a determined individual from visiting a website he wants to visit, but it makes viewing banned material sufficiently difficult that an ordinary citizen will not bother with the added hassle and will simply stick to censored web material inside of China.
Finally, the very existence of the Great firewall causes companies both domestic and foreign to engage in self censorship of their websites for economic reasons, which lessens the workload of the government censors. There are two reasons for this. First, China is already a huge market and it is growing quickly. When Google decided to create their Chinese website, google.cn, in 2006, there were approximately 100 million Chinese internet users; there are now about 200 million: a lot of eyeballs and a lot of potential revenue to give up, and something few companies are willing to do. While the leaders of public companies like Google may not like censorship, they have an obligation to their shareholders to maximize profits, which, because of the size of China, necessitates entering the Chinese market. The second reason companies create Chinese specific self-censored websites hosted in China is to compete more effectively with home grown Chinese websites. Chinese companies which host their websites in China give acquiescence to censorship in return for reliable, uninterpreted service. If foreign companies do not agree to censor their results, their websites will both still be censored by the Great Firewall and also be slower and less responsive because they must go through the Great Firewall. As an example, before Google created google.cn, in 2006, Google was losing market share in China to Baidu, a Chinese specific search engine.