Google PageRank (PR) is a link analysis algorithm developed by Google’s Larry Page and Sergey Brin in the late 1990s. Google PageRank contributes to your search engine ranking on Google search engine results pages (SERPs). Google PageRank is one benchmark for understanding the popularity of your web site based on the number and quality of sites that link to you. A high PR page that links to your web page will confer more PageRank to your page than an inbound link from low PR page.
According to Matt Cutts, Google’s spokesperson on SEO, PageRank values are published approximately once every 3 months. Therefore, Google PR is not an accurate metric for site popularity, as it is a cached value that is usually out of date.
Impact on Google PageRank
- Frequent content updates don’t improve Page Rank automatically. Content is not part of the PR calculation.
- High Page Rank doesn’t mean high search ranking.
- DMOZ and Yahoo! Listings don’t improve Page Rank automatically.
- .edu and .gov-sites don’t improve Page Rank automatically.
- Sub-directories don’t necessarily have a lower Page Rank than root-directories.
- Wikipedia links don’t improve PageRank automatically (update: but pages which extract information from Wikipedia might improve PageRank).
- Links marked with nofollow-attribute don’t contribute to Google PageRank.
- Efficient internal onsite linking has an impact on PageRank.
- Related high ranked web-sites count stronger. But: “a page with high PageRank may actually pass you less if it has more links, because it’s spread too thin.”
- Links from and to high quality related sites have an impact on Page Rank.
- Multiple votes to one link from the same page cost as much as a single vote.
HOW Google Pagrank works
- PageRank is only one of numerous methods Google uses to determine a page’s relevance or importance.
- Google interprets a link from page A to page B as a vote, by page A, for page B. Google looks not only at the sheer volume of votes; among 100 other aspects it also analyzes the page that casts the vote. However, these aspects don’t count, when PageRank is calculated.
- PageRank is based on incoming links, but not just on the number of them – relevance and quality are important (in terms of the PageRank of sites, which link to a given site).
- PR(A) = (1-d) + d(PR(t1)/C(t1) + … + PR(tn)/C(tn)). That’s the equation that calculates a page’s PageRank.
- Not all links weight the same when it comes to PR.
- If you had a web page with a PR8 and had 1 link on it, the site linked to would get a fair amount of PR value. But, if you had 100 links on that page, each individual link would only get a fraction of the value.
- Bad incoming links don’t have impact on Page Rank.
- Ranking popularity considers site age, backlink relevancy and backlink duration. PageRank doesn’t.
- Content is not taken into account when PageRank is calculated.
- PageRank does not rank web sites as a whole, but is determined for each page individually.
- Each inbound link is important to the overall total. Except banned sites, which don’t count.
- PageRank values don’t range from 0 to 10. PageRank is a floating-point number.
- Each Page Rank level is progressively harder to reach. PageRank is believed to be calculated on a logarithmic scale.
- Google calculates pages PRs permanently, but we see the update once every few months (Google Toolbar).
Pinpointing most of a website’s basic search-engine-optimization problems can be done in 20 minutes or less if you know what you’re doing. Take a look at the basics for an effective and fast SEO audit. Reading this infographic by Search Engine Journal can take more time than it does to actually perform the SEO audit itself. But in the end you will be fully prepared to improve your site’s visibility. So, take notes and improve your website.