In the field of SEO, as an industry that spread wildly and crazily at the end of 2009 - black links, are you familiar with it? Excluding the reference to the moral bottom line here, Ray only talks about what a black chain is from a technical perspective.
The meaning of black chain:
Black links are also commonly known as dark links. In layman's terms, they are hidden links. Users cannot see them on the website page, but they can be viewed in the source code and can also be crawled by search engine spiders. The website was invaded by hackers using technology, such as intruding into the website space through ftp weak password scanning and other means, and then uploading Trojans, etc., to obtain management rights, and by adding code, one or more export links were hidden.
Under normal circumstances, attaching a large number of black links to a website can quickly improve the ranking in a short period of time and bring one-way incoming links. In addition, the "get something for nothing" and the "high-quality and low-price" value-for-money offers have brought fatal temptation to many webmasters. However, in addition to being considered cheating by search engines, the biggest feature of black links is that they are not stable enough or even very poor. They are generally used in gray industries with huge profits, such as private server-type sites.
Some common black link codes
A: Hiding text through CSS styles is also a common method.
<div style="display:none;"><a href="">Link anchor text</a></div>
link anchor text
B: Make the link color the same as the background color by modifying the color. The link text is so small (less than or equal to 1 pixel) that it is difficult to detect with the naked eye.
<a herf=http://www.mianfeiseo.com/ style=”color:#FFFFFF;font-size:1px;line-height:1px;”>SEO Tutorial</a>
C: Control links through JS code
<script language=”javascript” type=”text/Javascript”>document.write(“<div style=’display:none;’>”);</script>
D: Move position advanced hidden layer via CSS
<div style=”position:relative”><div style=”position:absolute;left:0;top:0;z-index:999;width:90%;height:100px;border:1px solid #333;background :#eee”>Occlusion layer</div><div>Hide content</div>
There are also methods of placing black links through iframes and other methods.
Black links are so tempting that many people are eager to try them. When buying black links, Ray can't help but remind everyone, will buying black links be punished by Baidu? The existence of a product must have a lot of demand. However, how far an industry can go depends on healthy competition. As an industry regarded as cheating by search engines, how far can it go?
Original: SEO Tutorial Network Link to this article: http://www.mianfeiseo.com/2010/08/09/black-links/
Reprinting is welcome, please indicate the original source in the form of a link.
Thanks to phpxiaoguang for his contribution