A: For a couple reasons. At first, we figured that site owners or people running tests would notice, but they didn’t. In retrospect, we’ve changed other, larger aspects of how we look at links and people didn’t notice that either, so perhaps that shouldn’t have been such a surprise. So we started to provide other guidance that PageRank sculpting isn’t the best use of time. When we added a help page to our documentation about nofollow, we said “a solid information architecture — intuitive navigation, user- and search-engine-friendly URLs, and so on — is likely to be a far more productive use of resources than focusing on crawl prioritization via nofollowed links.” In a recent webmaster video, I said “a better, more effective form of PageRank sculpting is choosing (for example) which things to link to from your home page.” At Google I/O, during a site review session I said it even more explicitly: “My short answer is no. In general, whenever you’re linking around within your site: don’t use nofollow. Just go ahead and link to whatever stuff.” But at SMX Advanced 2009, someone asked the question directly and it seemed like a good opportunity to clarify this point. Again, it’s not something that most site owners need to know or worry about, but I wanted to let the power-SEOs know.
Page and Brin founded Google in 1998. Google attracted a loyal following among the growing number of Internet users, who liked its simple design. Off-page factors (such as PageRank and hyperlink analysis) were considered as well as on-page factors (such as keyword frequency, meta tags, headings, links and site structure) to enable Google to avoid the kind of manipulation seen in search engines that only considered on-page factors for their rankings. Although PageRank was more difficult to game, webmasters had already developed link building tools and schemes to influence the Inktomi search engine, and these methods proved similarly applicable to gaming PageRank. Many sites focused on exchanging, buying, and selling links, often on a massive scale. Some of these schemes, or link farms, involved the creation of thousands of sites for the sole purpose of link spamming.
where N is the total number of all pages on the web. The second version of the algorithm, indeed, does not differ fundamentally from the first one. Regarding the Random Surfer Model, the second version's PageRank of a page is the actual probability for a surfer reaching that page after clicking on many links. The PageRanks then form a probability distribution over web pages, so the sum of all pages' PageRanks will be one.
When we talk about ad links, we're not talking about search ads on Google or Bing, or social media ads on Facebook or LinkedIn. We're talking about sites that charge a fee for post a backlink to your site, and which may or may not make it clear that the link is a paid advertisement. Technically, this is a grey or black hat area, as it more or less amounts to link farming when it's abused. Google describes such arrangements as "link schemes," and takes a pretty firm stance against them.
One of the consequences of the PageRank algorithm and its further manipulation has been the situation when backlinks (as well as link-building) have been usually considered black-hat SEO. Thus, not only Google has been combating the consequences of its own child's tricks, but also mega-sites, like Wikipedia, The Next Web, Forbes, and many others who automatically nofollow all the outgoing links. It means fewer and fewer PageRank votes. What is then going to help search engines rank pages in terms of their safety and relevance?
1. Apparently, external linking of any kind bleeds PR from the page. Following or nofollowing becomes a function of whether you want that lost PR to benefit the other site. Since nofollow has ceased to provide the benefit of retaining pagerank, the only reason to use it at all is Google Might Think This Link Is Paid. Conclusion: Google is disincentivizing external links of any kind.
At one point, backlinks developed a reputation of damaging a site’s credibility through search engines. This is due to “black hat” SEO practices would add 5,000 links to a website overnight (a practice that is still used today). While the website would launch to the top of search ranking results for a few weeks, it wouldn’t stay there, and the site’s credibility would be damaged because a few dozen servers with thousands of useless websites existed for the sole purpose of creating backlinks.
Search engine optimization is a key part of online marketing because search is one of the primary ways that users navigate the web. In 2014, over 2.5 trillion searches were conducted worldwide across search engines such as Google, Bing, Yahoo, Baidu, and Yandex. For most websites, traffic that comes from search engines (known as "natural" or "organic" traffic) accounts for a large portion of their total traffic.