Nofollow misunderstanding

Absrtact: Before formally enters the topic, first brief introduction this nofollow how to use, believed also has some to do SEO friend to this label's use not to know very much: a target=blank href=abc rel=nofollowxxx concrete use is what? Before writing this article, my

In the formal to enter the subject, first of all, briefly introduce the nofollow how to use, I believe that there are some SEO friends of the use of this label do not know:

A target= "blank" href= "ABC" rel= "nofollow" >xxx

What is the specific use? Before writing this article, my understanding and many people like, add nofollow tag is to control the weight, that is, do not allow the weight of the page to be passed to the target page, thus, the relative increase of the weight passed to other pages.

This concept from when I was in the company to do SEO, it was buried in my head until I saw a blog post from Matt Cutts (the boss of Google's anti-cheating group) (~_~, of course, translated into Chinese) and summed up some of his cases to find out that the idea was wrong.

Nofollow This concept was originally proposed by Google in 2005, when the explanation of this label is mainly to cope with the increasingly rampant chain mass cheating, meaning that, as long as the addition of the nofollow tag link, the crawler will not be crawled.

(with additional instructions, because the vast majority of the chain is appearing in the blog or forum, when someone message and dispatch, through the platform itself program can be published by the user of the link plus nofollw tag, so in these platforms on the chain, the search engine itself will not increase its corresponding crawl workload, Because the search engine found added nofollow tag, it won't crawl. )

So where does our misunderstanding appear?

To give an image example:

For example your website page (page1), the PR value is 10, simultaneously this page has 100 links, that average, each link can obtain the weight is 10/100=0.1. If you add 50 of these links to the nofollow tag, that is, the weight of the 50 links to the transfer, theoretically the remaining 50 links to the weight will be: 10/50=0.2, but in fact, Each link to the weight or only 0.1, and not because of the use of NOFOLLW tags to change the PR value of the transfer.

In other words, the PR value of a single link does not follow the NOFOLLW attribute. With nofollow links, weights and strokes are not delivered, but it does not mean that the PR value that has not been passed is spread across other links.

Summed up is: a page in the face of a link to the weight of the output transmission, will not be because of your page to use how many nofollow and change the final transfer value.

So in turn think, we do SEO, NOFOLLW can help us?

The answer, of course, is yes. Let's analyze the principle, your new station, has 1000 pages, there are a lot of customer service help Ah, registration, login, user Agreement, and so on, the content of the page on the search engine, is no value, at the same time, even if the search engine crawled these pages, on your site itself SEO also help not.

Let's say there are 300 pages that are worthless to search engines, but what we know is, a new station, it is not possible to conduct a short-term search engine on all included, search engine principle is to first find your site, and then "live" in, according to the link of your page to crawl, and the amount of grab is assumed to be 100 a day ( Because we know that the search engine on the new site to capture the number of pages is not very satisfactory, it is recommended to see the previous written search engine like how the site.

So crawl through your 1000 pages, the search engine took 10 days, and there were some filters in the process, such as repetitive or similar content, and some worthless pages like login and registration, which could eventually be removed from the database again.

Now the problem is obvious, if you reasonable use NOFOLLW this label, some to enhance the website SEO not much value page link adds this label, the search engine nature saves a lot of invalid crawl time, to your website effective crawl will ascend, this, in the practice operation, is very useful , especially for the new station, as well as some large number of the consumer or some of the vast number of information on the Web site, reasonable use of nofollow tags, to enhance the search engine friendliness, you can effectively capture the promotion, to enhance your SEO traffic is also a very big help.