Don’t already have a blog?
Should you host you blog as a folder on your web site (or so that it appears to be a folder) such as www.domain.com/blog or as a sub web such as blog.domain.com or a completely different domain?
There are advantages to both approaches from a search engine perspective.
Advantages of hosting a blog as a folder on your main site
You could host your blog so that it appears to be a folder on your main site such as www.domain.com/blog. Here are the key advantages from a search engine perspective.
Improved rankings for your blog in the early stages
Search engines will likely consider the blog to be a part of the main site, even though it may be a sub web.
Assuming the main site has a decent linking position (Trust, Page Rank etc) “link juice” should flow from the links in the main site to the blog and help your posts reach higher rankings quicker than a standalone blog.
Add links to your blog from the main site, from both the common navigation areas of the site template(s) and from within the body of your web pages to specific posts as appropriate (for example, link to cases studies or additional tips in a blog).
Increased link popularity for the main site and blog
If you develop a useful and interesting blog and do a great job promoting it, your blog will build up links to it from other web pages in time. As this happens, the link juice should now flow from the blog posts to the pages on your main site helping those pages rank better.
Add links to the main web site from your blog from both the common navigation areas and from within the posts as appropriate. We’ll have more tips about this in a blogging tips part two article .
In other words, in time the link popularity of the combined main web site and your blog may increase. The links pointing to your blog should help improve the search positions reached by the entire web site.
Advantages of hosting a blog as a sub web or a different domain
There’s an important advantage to hosting your blog as a sub web such as blog.domain.com or as a completely different domain name.
Search engines will likely treat a sub web as a separate domain. If your blog is in a separate domain you may be able to get listings from both your main site and the blog in the results of some searches.
Using this approach you have a decent chance of getting multiple listings for your brand names. However it’s much less likely that you’ll get listings from both your main site and a blog ranking high for competitive non-brand phrases unless you do a fantastic job of promoting both your main site and blog.
For More Info
Free Blogs vs. Hosting Your Own Blog: Pros and Cons: Aritle on Web Marketing Today July 2010