Because of the frequency of active blogs (daily - or at least 5 times a week) the search engines have put high weight on blogs that are focused and tend to stay on topic.

It’s the freshness of content (in a perfect world) that a search engine is craving and rewarding to the blogs. The ideal situation is that the blog would provide for tiny snippets of information that over time build up to a greater whole. (Almost like a blook)

But the most overloooked element of a blog is that once you’ve established a frequent pattern of posting and you have the Googlebot coming to your site every few days, you can then use that to link to other sites, sub-domains or any deep links that you need to get crawled. While most blog postings may not have direct links to any sites in particular, you could always format your blog with some permanent links on the side.

Another mistake made by the amatuer blogger is that they don’t realize that you can optimize your blog. True, most blogs only have a few areas, namely the "home" page and the "archive" page. But depending on the tool being used to post the blog, there are some places where you can take advantage seo-wise.

The title of your blog should be thought of as a headline - grab the reader’s attention - but also be sure that your blog title is also what gets archived - that way your titles can become search queries as well.