This question came in recently from a small business client, who wanted to understand why a blog might be useful - here's our short answer....
"Basically, it's a way to get new material, specifically concerning your business and capabilities (and laced with great keywords), out there on the Internet on a frequent basis. Especially if you can't (or it doesn't make sense to) update the primary website very frequently. Search engines love fresh, relevant content, and sites that get updated frequently. It's simply good for SEO.
For your small business purposes, the blog is basically just an easy content management system - i.e. you can upload content without having to do any programming (HTML coding). Plus it allows you to tag things, and automatically does things for you (like pinging update services, creating RSS feeds, archiving posts, etc.), and it's another category of "site" that Google likes to search, that you don't have to worry about (like you would have to worry about when updating a regular website).
So, the first objective of the blog is just to get more great content out there, with keywords and links to you, for search engines to find. Secondary objectives might be to actually make the blog a destination, to discuss things with customers, receive comments (moderated), share "behind-the-scenes" news", whatever. However, most mature blog destinations are only blogs, that is, they're not substitutes or proxies for regular websites. The best long-term thing to do is to actually host blog capabilities right on your own site.
We actually do this with "Gateway to Loudoun County".....our main site is www.dullessouthonline.com
, and the blog is at http://www.dullessouthonline.com/loudoun_county_gateway/
. Note the blog is under the Dulles South domain.
Now, in order to "capture" sales, you should be focusing your visitor traffic to your primary "landing page", that is, the page that says "we're great, cheap, you need us, call now...". So the blog shouldn't be that page, but should funnel readers to it. All external links on other websites should be to that page, which in most cases is your own home page."