Advantages and Disadvantages of Business blogging

As the blogging technology becomes even more incorporated into the corporate identity, it is important to catalog the pros and cons of putting your business in such a public place, and how potential impacts it can have.

As they detail in the article, Advantages and Disadvantages of of Business Blogging
the primary benefits of blogging can be summed up like this:

Cheap, easy publicity: blogging has a relatively low overhead cost, and it essentially networks itself if you set up your exposure correctly. But it has its pitfalls, as discussed below.
Instant Feedback: Blogging has the feedback set-up of a lecture hall, where the blogger provides the content, and the rest of the blog's existence is essentially and electronic Q&A session.
Personality: Setting up a blog, especially for the large corporations like Sun Microsystems, GM, and Nike allow the sometimes "faceless" corporation to have voice in the form of a single blogger. That can the CEO, a technical expert, or a designer, voicing opinions and putting a personal touch to the business.
Community: blogging exists as a social network of information and content sharing, so participating in others blogs, commenting, and re-posting aids in that.

The cons for businesses must be recognized as well:

Cheap, easy publicity: for the same reasons it is an advantage, a blog will make it easy to make statements that will be publicly exposed and archived forever, even the wrong ones.
Constant Maintenance: A blog is a time-stamped entity, so any gaps in timely posts may push your blog out of a reader's top-eight, and you will disappear from the RSS feeds.
Dealing with Private Information: A blog is visible to everyone: employees, competitors, scammers and the government, among others. So the content must be carefully prepared with this in mind.
Credibility: in the Blogosphere, authenticity is key to building a reputation that draws in readers, which can take a long time, and be gone almost instantly. Things like typos, appearing like a disingenuous corporate jingle writer, or blatant advertising disguised as content will take the air right out of blog.