When Google first opened their search engine in the late 1990′s it revolutionized the way people found information online. Google came along with a way to show the best results at the top of search results. PageRank (a trademark of Google) is what made this possible. Understanding how it works is vital if you want to make your site show up higher in search engines.
PageRank is a numerical score. The higher the PageRank, the more important and authoritative the web page. It’s assigned to every page that Google indexes. Basically, PageRank is the likelihood that someone clicking links at random will visit a particular page.
Google uses PageRank to figure out what results to show first. It figures out what pages are most relevant to the phrase that was searched for. Then, it filters and sorts those results based on PageRank.
PageRank is calculated by looking at all the links pointing to a given web page. Each link is like a vote of confidence from a third party.
The amount of PageRank gained from a link depends primarily on two things:
- The PageRank of the page the link is on (The authority of the third party)
- The number of links on that page (How discriminating the third party is with their votes.)
Think of PageRank as a liquid– link juice. The higher the PageRank of a page, the more juice it has to spread around. Links are like pipes that share that link juice to other pages. The number of links determines how much juice gets shared with each linked page.
For example, if The White House linked to you from their home page, Google would see you as being very, very important. The White House doesn’t have any links to other websites on their home page, and that page has one of the highest PageRanks around.
If you got a link from some deep page on a no-name site with hundreds of other external links on it, it would do next to nothing for you.
In recent years, Google has gotten more sophisticated in how PageRank gets calculated. Links at the bottom of a page pass less juice than links in the middle of the body text. Also, links found on every page of a site (Run-of-the-Site Links) don’t count for much.
That’s what’s important to understand. Every link is not created equal.
What’s not important is getting caught up on your actual PageRank score. Google won’t tell you the exact score, but they’ll give you a rounded off estimate that’s a few months old if you install their toolbar. That doesn’t do you a lot of good, and PageRank doesn’t take relevance into account anyhow.
What you should keep an eye on is where you show up in actual search results. Go to Google and search for what you offer. Where you show up is what matters, and getting good links can help you move up.
Google sometimes personalizes results based on your past search behavior. If you’re seeing a customized page of results, there will be a link at the bottom of the page labeled “View Customizations.” Click that, and then click the “without these improvements” link to see the raw results.
If you want a more exact explanation of PageRank, you can always read the patents that have been filed.
Note that there are also links that don’t pass any juice. If, in the source code of a webpage, a link has the attribute rel=”nofollow” then Google will not transfer any PageRank juice through that link. It’s still good to have those links pointing at your site because people can click them to get to your site and search engines may still use them as clues to the subject of your site.
I’ve tried to make this as simple as possible, but it’s a complicated subject. If you have a question or know something I left out, leave a comment below!