Link weight is a specific contribution of each link to website promotion in search engines, which is transmitted from donor to acceptor. Each link has its own weight, which is taken into account when ranking sites in the search results. Priority is given to the sites with the highest indicators.
One of the first indicators of link ranking is based on the transfer of link weight - the PageRank (PR) algorithm. The creators of each search engine over time improved this algorithm, complicated it, thereby reducing its impact on the overall relevance of the document. However, at the core of all link algorithms of search engines is the idea of PageRank, which was created in 1996 by S. Brin and L. Page, only complicated and improved.
Based on the analysis of the link graph, PR is calculated - the probability with which the user can go to the page. This probability is determined by adding the transition probabilities for all the links that lead to this page. In turn, each of these probabilities is determined by the probability of visitors coming to the donor page, etc. So, with the increasing likelihood of going to a page, the credibility of this page grows.
Currently, the weight of a link depends on its characteristics, on the quality of the donor and on the clickability of the hyperlink.
The classic formula for calculating PageRank:
PR - PageRank of the page,
d - the attenuation coefficient (this is the probability that the user will click on one of the links after entering the page, and not interrupt their stay in the network, usually according to the classical formula, it = 0.85).
PRi - PageRank of the i-th page that links to the page in query,
Ci - the total number of links on the i-th page.
The essence of the PageRank algorithm is that the page transfers the weight that is distributed to outgoing links. As the number of links on the donor page increases, the weight for each acceptor page decreases.
How the link weight is transmitted
To create effective linking schemes, it is important to be able to calculate the link weight in order to provide a complete picture of external and internal promotion. There are no exact calculation instructions, but experts have experimentally identified the main patterns. Let's take a concrete example.
Initially, the indicator for each site page is set to 1. for Example, the main page (G) links to two second-level pages. Of these, one has a backlink (V1), and the other doesn't (V2). One of the pages of the second level (V1) is referenced by the page of the third level (V3).
Now we are counting. All donors transmit their weight with attenuation, so a coefficient of 0.85 is transmitted instead of 1. That is, from any transmitted page, the indicator will be at least 0.85.
The link weight that the donor can transmit is divided among all acceptors (recipients). For example, the page contains 3 links. In this case, each will get a weight of 0.85 / 3, i.e. approximately 0.28. As a result, in order to calculate which indicator will be transferred to the page, you need to consider all incoming and outgoing links.
Which links transmit and don’t transfer weight
It’s important to understand which links will positively influence the promotion and which will aggravate the situation. All links to your site can be divided into 3 groups:
- transmit static weight and participate in anchor promotion;
- transmit static weight, but do not participate in anchor promotion;
- useless links that do not transfer weight and do not participate in anchor promotion
Active ones are the basis of the link building. These are links that the user can click on to go to the main or any other page of the site. As a rule, the link building consists of active links. Usually, they are open for indexing and navigation by search robots.
Inactive - almost useless, but at the same time necessary links. You cannot click on them, and the user will have to copy the URL and paste it into the address bar. They do not transfer weight, are not available for indexing, but are part of the total link building, diluting it and creating a more natural growth effect.
Active links are divided into the following types:
Direct - The URL of the link is exactly the same as the address of the site that you are going to.
Redirect - the URL of the link does not match the URL of the site that the user goes to. They can't be used for promotion and don't pass reference weight.
Direct links are:
- with a symbolic anchor - The links with the keyword specified in the text. These links carry a lot of weight;
- with the noindex tag - If a link in the code is enclosed in the <noindex></noindex> tag, its text will not be indexed by the search engine, so it will not pass anchor weight;
- with attribute nofollow - If the link tag contains the value of the attribute rel = "nofollow", then this link will not be taken into account by the search engine and will not pass weight;
- with noindex + nofollow tags - Some donors can use 2 tags at once to prohibit indexing and prohibit reference weight accounting. Useless in promotion;
- anchor with an image - Such links may transmit the full weight, but they do not participate in the ranking. They do not affect the promotion of certain queries;
- non-anchor - Links in which adverbs are used (“here”, “there”), brand, page address. Needed to dilute the total reference mass and its naturalness.
Factors that reduce the weight of the link
If you buy or sell links, it is important to consider factors that together can seriously reduce weight. Here are the main ones.
- Backlinks (when two sites exchange each other). They have the least weight since the search engine understands that this is an exchange.
- Links from non-thematic resources (you have a site about cats, and links are posted on resources about cars).
- A large number of links from one page of the donor to different resources (as we said earlier, the link weight is distributed between all acceptors).
- Site spamming. It is recommended that you check the trust of all sites where links are purchased.