Six Types Of Business Blogs(Fredrik )
http://www.corporateblogging.info/2004/08/six-types-of-business-blogs.asp Corporate (or Business, Organizational) blogs can be classified into six different categories. Each category shares common characteristics and the blog content can be expected to differ between the categories. Furthermore, there’s differences in terms of target groups and purposes. Even if we also see hybrid forms where blogs are examples of more than one category, an organization that professionally incorporates blogging into its communications strategy will likely prioritize one purpose (for each blog). 
Sales blogs - external Purpose: To market or sell products/services, make citizens aware of public services, get donations for charities or political parties etc. Blogger: The organization itself, or more specifically individuals within it writing on behalf of the organization. Target groups: (Potential) clients/customers and citizens, that is persons and/or other organizations that are directly involved with the publishing organization, or those it wants to reach with the purpose above. Relationship blogs - external Purpose: To create, uphold or strengthen relationships. Blogger: The organization itself, or more specifically individuals within it writing on behalf of the organization. Target groups: Often smaller and more specified than with sales blogs. Examples are support blogs aimed at customers of a certain product, finance blogs for IR purposes, PR blogs for media, blogs trying to reach students, future employees, politicians/officials etc. Branding blogs - external Purpose: To strenghten the brand, the profile, of the publishing organization or individuals within it. Blogger: Not necessarily the organization itself. Individual employees’ or executives’ blogging (“insider blogs”), if supported by the organization, can be viewed as a branding blog. The same goes for adverblogs and blogs that are not apparantly connected to the organization. Target groups: See Relationship and Sales blogs. Knowledge blogs - internal Purpose: To give employees information and insights relating to their work assignments; news, business intelligence, reports about ongoing projects etc. Blogger: The organization itself through one or more designated bloggers, or potentially all employees through a entirely open blog publishing model. Target groups: All employees with a certain interest. Collaboration blogs - internal Purpose: To provide a working team with a tool for research, collaboration and discussion. Blogger: The team. Target group: The team. (There’s only a fine line - if any - between this blog category and business wiki’s. You could also see for example Relationship Blogs change into more wiki-like publications.) Culture blogs - internal Purpose: To strengthen organizational culture. Typically through informal content of social or non-work related character. Blogger: The organization itself through one or more designated bloggers, or potentially all employees through a entirely open blog publishing model. Target groups: All employees as employees, and not as professionals (developers, managers, assistants and so on).