Having looked at how existing content creates value, it is important to recognize how it is that off-page content can serve to exponentially increase the value of the fundamental keyword anchors that are created by on-page content.
By linking in contextually relevant content to on-page articles we are able to achieve a benefit of scale, in that many links can be directed inbound to a single page. The net result is that the on-page content will improve in quality in the eyes of the search engines, and therefore produce a greater amount of organic traffic. The way we do this is by understanding how it is that the Page Rank metric (from Google of course) helps us to value the net benefit of inbound links and their on-page contextual anchoring)
In general, SEO professionals have been able to ball-park the comparative values of different page ranks into a basic PR table. This table illustrates the kind of scale that search engines use to value a PR1 link in comparison to a PR2. In general, this table is summarized as follows:
While this chart serves only as a mathematical demonstration of the comparative values, it provides a useful tool for understanding the difference between each incremental page rank. This essentially means that a single inbound link from a PR10 website is worth almost 10 million times more than a link from a PR1 site. That being said, this does not necessarily mean that the PR10 link is worth $10 million dollars, it simply suggests that the time and effort value of the link is extremely high, to the point at which procuring them could be seen as a competitive advantage.
With these link values in mind, we can then proceed to use a back-link indexing tool to determine what kind of value off-site content is creating for the page. By discounting the value of these inbound links in accordance to a weighted average of their relative value, and then taking into account the value of the keywords that they are referencing into the site, we are then able to determine a tangible value for the value created by the inbound links.
Ideally, we can then identify value-opportunities by looking at the cost-benefit break even of procuring hundreds of cheap links from off-site content, or focusing on developing high-quality links from guest-posts in order to boost page-rank efficiency.