It is a well-known fact, for example, that links coming from blogs are especially helpful in improving your rankings. What most people don’t know is why exactly that is the case.
One must realize that one of the most powerful types of link exchanges known to man is a site-wide sidebar exchange between two blogs, also known as a blogroll exchange. Such an arrangement, in effect, creates the potential for each party to receive hundreds (or even thousands) of relevant backlinks. This is due to the fact that each and every page of Site A links to the homepage of Site B, and vice versa. As you can see, an exchange like this between two very large sites can be of great benefit to both of them.
Another much smaller scale type of blog link is a simple reference from another post. These usually aren’t part of a reciprocal agreement, and might at first glance, appear to be quite minor. In truth, however, these links carry a lot of weight, due to their high level of relevance.
I mean, think about it for a minute. Most bloggers won’t link to another post unless it’s clearly related to what they’re writing about. And links from highly relevant content-based pages are going to be valuable assets, regardless of pagerank, etc.
http://all-seo-tip.blogspot.com/search/label/Backlinks
