Calculating link juice value of backlinks to webpages

 Firstly, what is a backlink? A backlink is a link on one page on the Internet to another. Typically, backlinks are indicated by blue text with an underline but this is by no means universal. Here we have some backlinks and the text is in grey. A backlink may link to a page on the same website. This page is from EzineArticles.com and this link is to another page on EzineArticles. These links, however, go to different websites and they are therefore external links whereas this one is an internal link.

Link juice is the term coined by Greg Bowser for the currency of backlink value. The amount of link juice available from each webpage is indicated by its PageRank. A webpage with a PageRank of 6 will have six times the amount of link juice available compared to a webpage with a PageRank of one. The quantity of link juice passed on from a webpage will depend on the number of outbound links. Here we have two webpages with an equal quantity of web juice released to this one page will be sixfold the quantity of link juice passed from the webpage with six outbound links.

Here we have five webpages. Two with PageRank 6,  two with PageRank 1 and one with a PageRank 0. The webpage with PageRank 0 has no link juice and therefore releases no link value, no link juice, to any page that it links to. These two pages both have PageRank 6. This one has one outbound link and this one six. The total link juice to the one linked page here is six times the quantity of link juice to each page of the six linked out by that page.

These two pages have PageRank 1. This one has only one outbound link and that link value, the amount of link juice, is equivalent to the link juice provided from this PageRank 6 webpage that has six outbound links. This page has a PageRank 1 and six outbound links. it has 1/6th the value of the link juice to each outgoing link. All the link juice produced will go into the bottle of the receiving webpage which then has its link juice and therefore from the link juice total, the PageRank can be calculated by Google.

 Matt Cutts, who heads the spam detection unit at Google, and acts as Google's spokesman, describes link juice in the following way. Here, he shows link juice coming in to two pages. This one receives 100 units of link juice and this one receives nine units of link juice. This one has two outbound links and each will therefore have 50 units of link juice. This one has three units of link juice and each link conveys three units of link juice.  This page, therefore, has a total of 53 units of link juice because it has an incoming link with 50 units and another with three units.This one has 50 units of link juice because it receives just 50 from that page. The link juice is then passed on.

 Matt Cutts also explains that the system would implode if there was not a small reduction made each time the link juice passed on.

You can determine the number of links to a webpage by typing into a search box link:pageURL.  When you click on search, the search engine returns the total number of links. For my website Keyword SEO Pro, there are currently 6650 backlinks. The search engine also shows the various links that are in this number.

There are two useful backlink number tracking programs - Link Popularity Check and Site Popularity.

This is Link Popularity Check. You add in the domain names that you want to determine the number of backlinks for. Here we have Keyword SEO Pro. You can see the number of backlinks on AllTheWeb, Altavista, Bing, Google and Yahoo. Note that Google tends to reflect a very low number. This seems to be because Google only lets us see the links it has in its database that have PageRank of at least 3.

Site Popularity similarly looks at the backlink numbers to Google, Yahoo, Altavista and AllTheWeb. It was gives information on PageRank, Alexa position, and whether the site is on DMoz. An additional advantage of Site Popularity is that it will look at the backlink numbers to internal pages. This is not the case with Link Popularity Check. One disadvantage is that this program, at least as far as the free version is concerned, will look at only 10 webpages.

Backlink Watch is a free program that will look at PageRank, total number of outbound links and the total number of backlinks to a URL. It has the disadvantage that there is no means of exporting the data for further analysis.

At this time, SEO Spyglass seems to be the leading backlink analyser. You enter the URL and the program seeks out all the links to that page. It will then analyse for a number of factors including the PageRank of the linking page, the number of links, the total number of links on that linking page and it calculates the link value. The link value from each page is approximately the PageRank divided by the total number of links. SEO Spyglass allows for the slight reduction in link juice quality. As Matt Cutts has explained, if this was not the case, the PageRank system would implode.

Finally, you will need a program to monitor progress in terms of positioning on search engines. I recommend Rank Tracker. This is the results for a client, who wished to rise up the positioning for 'gutter cleaning' in the Essex and London area. One of the keywords he wanted top position for, was 'gutter cleaning in Romford' and here you can see the results in tabular form showing the change in positioning and all these are positive and for this keyword on Google.co.uk you can see the positioning once we started a backlinking campaign and it's now in position one.