Addressing "uncontrollability' of online buzz, this thesis examines unstructured user-generated content in response to corporate social responsibility communications in the blogosphere and explores the content of company-administered co-creation communities. Analyzing text-based content online, the study unravels noteworthy patterns of online buzz that companies should monitor among the vast information circulated on the internet. The findings suggest that in the context of corporate social responsibility communications, to maximize the efficiency of corporate communications and have a better control of user-generated content online, it seems worthwhile to establish a portal with a clear target audience. Engaging in direct communications via structured communities may help generate "fans" and reduce the proportion of negative responses from non-specific internet users. However, setting up company-administered communities did not necessarily lead to "controlled" content. User opinions appear to be influenced more by fellow users than by companies. In developing co-creation platforms, it is particularly critical to monitor the development of user collective emotion as it may have a direct impact on community performances, namely, creativity and user participation. Notwithstanding the above, it is worth noting that the "collective" online buzz may actually be under the influence of only a few that voice their thoughts first. In dealing with user-generated content online, it is important for companies to be aware that the "uncontrollable" may be predicted by some controllable factors, whereas the "controllable" may be influenced by some uncontrollable factors.