The other day a friend of mine asked me about setting up a blog. He’s planning to lay the foundation of an internet business and is following a blue print that lays out all the steps to be successful. Blogging is part of the process. In the course of the conversation, I mentioned one alternative to installing a blog in a folder. That alternative is using a subdomain for the blog. He asked some good questions about the pros and cons. I had a few ideas about it such as using a folder being a little simpler, but a blog would have a more distinct identity in a subdomain while still having a relationship to its parent domain. But there are other considerations as I learned after doing a little research. A lot of it depends on your goals and the size of your web site.
If you intend to do nothing but blog on your domain name, then by all means, just install your blog in the root of your web hosting account and have your visitors come directly to your blog when they enter your web address. But if you intend to have a separate website that stands on its own, it’s time to consider the pros and cons of using a subfolder or a subdomain. For those of you who are ambitious, big thinkers and you envision building out a large and complex site, subdomains can be helpful to separate distinct areas of subject matter. This is also useful to improve search engine indexing and rankings. Search engines treat sites in subdomains as unique sites. So if you provide good content with links back to your primary site in your subdomain blog, this can improve search rankings if done properly. See this tip sheet from Net Mechanic for some of the potential pitfalls. Try this search for more information on the question.
Here’s an example of an organization that’s using a subdomain for their blog. As you’ll see in the blogroll at the bottom of the left column, there’s no one-size-fits-all answer. Learn a little and take your best shot. You can always make changes if needed.