How Link Value is Determined by Google PageRank
When it comes to Google’s PageRank system, not all web page links are created equal. Google determines how valuable a web page is by assigning it a given PageRank from 1 to 10, with 10 indicating that the web page is of high value and has a high probability of being visited by a random web surfer. Google’s PageRank system relies in large part on the links that are listed on the web page. Link type, number, placement, font size and position all play a part in how Google determines whether a link will be followed by a web surfer. In fact, Google even filed a patent on the method by which it assigns PageRank to web pages, a method that makes link quality a high priority.
A web page is likely to be assigned a high PageRank if several high PageRank or many low PageRank web pages link to it. A combination of the two situations can also occur. However, link number and PageRank are just the start of how Google assesses PageRank. The source page on which the link appears and the page to which the link directs the web surfer are additional features that are analyzed by the search engine. Google may also calculate which links are the most frequently clicked on by web surfers and which keywords are used to find the web page. The location of the given link is also important; a link that is placed at the start of a web page is more likely to be clicked on by a user than a link placed at the bottom.
Some additional link features that Google takes into consideration when determining PageRank are anchor text size, list placement (top, middle or bottom), word number, font size, appearance (image versus text) and target URL size. Relevance of the link to the web page’s content is also key, as well as whether the link being used is commercial (or not). User interest in the web page, determined by such factors as link click number, duration of target URL visit and repeat page visits, is also vital.
In conclusion, Google takes many link features into account when determining how much value they add to a web page. These link features help calculate PageRank, which is not only an estimate of a web page’s likelihood of being found by users, but also an estimate of its intrinsic value.
A detailed Google patent analysis is available from here: http://www.seobythesea.com/?p=3806