An external blog is a publicly available weblog where company employees, teams, or spokespersons share their views. It is often used to announce new products and services (or the end of old products), to explain and clarify policies, or to react on public criticism on certain issues. It also allows a window to the company culture and is often treated more informally than traditional press releases, though a corporate blog often tries to accomplish similar goals as press releases do. In some corporate blogs, all posts go through a review before they're posted. Some corporate blogs, but not all, allow comments to be made to the posts.
External corporate blogs, by their very nature, are biased, though they can also offer a more honest and direct view than traditional communication channels. Nevertheless, they remain public relations tools.
Certain corporate blogs have a very high number of subscribers. The official Google Blog is currently in the Technorati top 50 listing among all blogs worldwide.
Marketers might expect to have product evangelists or influencers among the audience of an external blog. Once they find them, they may treat them like VIPs, asking them for feedback on exclusive previews, product testing, marketing plans, customer services audits, etc.
The business blog can provide additional value by adding a level of credibility that is often unobtainable from a standard corporate site. The informality and increased timeliness of information posted to blogs assists with increasing transparency and accessibility in the corporate image. Business blogs can interact with a target market on a more personal level while building link credibility that can ultimately be tied back to the corporate site.