Here is an interesting article from Working Knowledge from the Harvard Business School.

a blog is an incredibly effective yet low-cost way to:

• Influence the public “conversation” about your company: Make it easy for journalists to find the latest, most accurate information about new products or ventures. In the case of a crisis, a blog allows you to shape the conversation about it.
• Enhance brand visibility and credibility: Appear higher in search engine rankings, establish expertise in industry or subject area, and personalize one’s company by giving it a human voice.
• Achieve customer intimacy: Speak directly to consumers and have them come right back with suggestions or complaints—or kudos.

Go to the link above to read the entire article.