The business value in having your employees blog is that the more they participate in the development community, the more likely you as an employer will reap the benefits from it. Specifically, if your developers are actively participating in the community, chances are they are more likely to be exposed to a variety of techniques, perspectives, and opinions beyond those in your own company. Likewisem they will be able to share their experiences, good and bad, for the benefit of others.
Does this provide add a measurable value to your business? I would say that would be hard to determine. But, as your employees represent your company to the developer community, it can be a double-edged sword depending on the topics discussed. If your developers are making intelligent posts about technologies they know well, it can definitely go a long way to associating your company name with those who are in the "know".
Oh Business Value, where art thou?
I can see why a software vendor, such as Microsoft, would want to blog about their products. In the end it helps to sell the software. Yes I know there are other reasons like it raises awareness, puts a human face on the product, etc. But in the end these just make someone more likely to go out and buy the bits.
But I work for a small IT consulting firm. We sell consulting, not software. So what kind of payback does blogging bring? The business people that hire us do not read technical blogs. Blogging might raise awareness among developers, but developers are never keen to bring in someone that might make them look bad.
Any thoughts on whether blogging could bring business value to a consulting firm? If so, how? If not, why not?