From a business perspective there are several potential reasons to blog:
"Become the Expert
People's position and their company as the thought leader of your business.

Customer Relationships
In a forum where people's main objective not is to sell, they'll have a more personal relationship between you and their customers. Blogs are a fast way to join the customers' discussions, provide tips and insights or receive feedback.

Media Relations
It's every PR-consultants dream to create a channel where media regularly check what they have to say, instead of media just being passive - sometimes indifferent - recipients of press releases.

Internal Collaboration
Use blogs as a workspace where project members keep each other updated without wasting time writing reports or searching the Outlook inbox.

Knowledge Management
Blogs works in two ways. First of all, they're an easy way for the readers to find information and resources they want or need. That's obvious and could be used internally in many organizations. Second, blogs are a kind of "university light" for the blogger. Blogging is on-the-job learning.

Recruitment
If people establish their company as a thought leader, people in your business will pay attention. They'll read and discuss what they have to say. Chances are good they will see they as an attractive employer.

Test ideas or products
A blog is informal. It's part of a conversation where people (often) can comment, and the blog can provide they with a measure of value.

Rank high in search engines
Well, this has nothing to do with relations. But Google and other search engines rewards sites that are updated often, that link to other sites and most importantly, that has many inbound links. Start a blog at your regular site and your ranking will boost."

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