A web ring is group of related web pages linked to each other in a sequence that forms a ring. When someone searching the web stumbles across one of the web ring’s pages, they can click through to other sites that have related content. Web content-providers can add their pages to the ring by ‘linking in’ to the ring so that web surfers are more likely to encounter their site. Web rings usually have a moderator who controls which pages are ‘related’ and which are orthogonal to the purpose of the web ring.

The intent of the participants of a web ring is not to deceive search engines, and in this sense, this can be considered a white-hat search engine optimization technique.

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On the World Wide Web, a link farm is any group of web pages that all hyperlink to every other page in the group. Although some link farms can be created by hand, most are created through automated programs and services. A link farm is a form of spamming the index of a search engine (sometimes called spamdexing).

History

Link farms were developed by search engine optimizers in 1999 to take advantage of the Inktomi search engine’s dependence upon link popularity. Although link popularity is used by some search engines to help establish a ranking order for search results, the Inktomi engine at the time maintained two indexes. Search results were produced from the primary index which was limited to approximately 100,000,000 listings. Pages with few inbound links continually fell out of the Inktomi index on a monthly basis.

Inktomi was targeted for manipulation through link farms because it was then used by several independent but popular search engines, such as HotBot. Yahoo!, then the most popular search service, also used Inktomi results to supplement its directory search feature. The link farms helped stabilize listings for (normally) online business Web sites that had few natural links from larger more stable sites in the Inktomi index.

Link farm exchanges were at first handled on an informal basis, but several service companies were founded to provide automated registration, categorization, and link page updates to member Web sites.

When the Google search engine became popular, search engine optimizers learned that Google’s ranking algorithm depended in part on a link weighting scheme called PageRank. Rather than simply count all inbound links equally, the PageRank algorithm determines that some links may be more valuable than others, and therefore assigns them more weight than others. Link farming was adapted to help increase the PageRank of member pages.

However, even the link farms became susceptible to manipulation by unscrupulous Webmasters who joined the services, received inbound linkage, and then found ways to hide their outbound links or to avoid posting any links on their sites at all. Link farm managers had to implement quality controls and monitor member compliance with their rules to ensure fairness.

Alternative link farm products emerged, particularly link-finding software that identified potential reciprocal link partners, sent them template-based emails offering to exchange links, and create directory-like link pages for Web sites hoping to build their link popularity and PageRank.

Search engines countered the link farm movement by identifying specific attributes associated with link farm pages and filtering those pages from indexing and search results. In some cases, entire domains were removed from the search engine indexes in order to prevent them from influencing search results.

Justification

The justification for link farm-influenced crawling diminished proportionately as the search engines expanded their capacities to index more sites. Once the 500,000,000 listing threshold was crossed, link farms became unnecessary for helping sites stay in primary indexes. Inktomi’s technology, now a part of Yahoo!, now indexes billions of Web pages and uses them to offer its search results.

Where link weighting is still believed by some Webmasters to influence search engine results with Google, Yahoo!, MSN, and Ask (among others), link farms remain a popular tool for increasing PageRank or perceived equivalent values. PageRank-like measurements apply only to the individual pages being linked to (typically the reciprocal linking pages on member sites), so these pages must in turn link out to other pages (such as the main index pages of the member sites) in order for the link weighting to help.

The expression “link farm” is now considered to be pejorative and derogatory. Many reciprocal link management service operators tout the value of their resource management and direct networking relationship building. The reciprocal link management services promote their industry as an alternative to search engines for finding and attracting visitors to Web sites. Their acceptance is by no means universal but the link management services seem to have established a stable customer base.

Guidelines

Google indicates in its Webmaster Guidelines that more than 100 factors are used to determine search results rankings. There is considerable debate in the search engine optimization community regarding the continued value of PageRank. Mike Grehan, a well-known search engine optimization columnist, has publicly quoted engineers from Yahoo! and Ask who say Google never fully implemented their PageRank algorithm.

Search engines such as Google recommend that webmasters request relevant links to their sites (conduct a link campaign), but avoid participating in link farms. According to Google, a site that participates in a link farm may have its search rankings penalized.

Search engines try to identify specific attributes associated with link farm pages and filter those pages from indexing and search results. In some cases, entire domains are removed from the search engine indexes in order to prevent them from influencing search results.

Links

• Google Information for Webmasters, accessed 2005-09-03.
• Yahoo!’s Search Content Quality Guidelines

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia.

A Free For All link page (FFA) is a web page set up ostensibly to improve the search engine placement of a particular web site.

Webmasters typically will use placement software to place a link to their site on hundreds of FFA sites hoping that the resulting incoming links will increase the ranking of their site in search engines. Experts in search engine optimization techniques do not place much value on FFAs. First, most FFAs only maintain a small number of links for a short time, too short for most search engine crawls to pick them up. The high “human” traffic to FFA sites is almost completely other webmasters visiting the site to place their own links manually. Search engine algorithms do more than count link numbers, they also check relevancy which the unrelated links on FFA sites do not have. Another drawback to FFAs is the amount of spam webmasters will receive from the owners and paying members of the FFA. Using an FFA can be considered a form of spamdexing.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia.

A reciprocal link is a mutual link between two objects, commonly between two websites in order to ensure mutual traffic. Example: Alice and Bob have websites. If Bob’s website links to Alice’s website, and Alice’s website links to Bos’s website, the websites are reciprocally linked.

Website owners often submit their sites to reciprocal link exchange directories in order to achieve higher rankings in the search engines.

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Link Exchange (“Reciprocal Link Exchange”) is the practice of exchanging links with other websites. There are many different ways to arrange a link exchange with webmasters. The simplest way of doing it is to email another website owner and ask to do a link exchange. Also visiting webmaster discussion boards which offer a dedicated link exchange forum where webmasters can request a link exchange be it of a certain category or open to anybody. You place their link on your site, usually on a links page and the other site in return will place a link back to you.

Link exchange has been a long time practice by website owners since the beginning of the WWW. In the last few years (after year 2000), this practice has gained more popularity as search engines such as Google started favoring sites that had more links in the rankings. This system was very accurate at gauging the importance of a website when it first started, leading to the popularity of Google

However according to experts, search engines no longer place a heavy emphasis on reciprocal links. Instead the popularity or credibility of your site is now gauged by one way incoming links to your site. How than do you go about building one way back links to your site? There are a number of proven techniques you can follow:

1. First and foremost your aim should be to link to sites with a similar theme as your site. For example if you site is about “dogs” than it makes sense that back link from another dog or animal related site would be given a heavier weighting that a link from a casino site. You should start by conducting a search with you keywords on the major search engines (MSN, Yahoo, and Google) to come up with a list of sites which appear for that keyword. Next determine the contact info, ideally an e-mail address. Once you have this information, you can simply contact the webmaster (politely) and ask them if they would be willing to link to your site.

2. Another effective way of increasing your link popularity is to write and submit your articles to sites such as articlecity.com. The importance of this is that when you submit your material there is usually a resource box where you can enter the link information to your site. Every time someone publishes your article, you will have a one way link from their site to yours.

3. Submit to directories under the appropriate category. Many directories and human edited and therefore a link from a directory can instantly add credibility to your site. A major directory is Dmoz. Since site submissions are human reviewed, expect at least 6-8 weeks for any kind of response.

4. Submit your URL to link exchange directories where web users such as your self are actively looking to find new relevant link partners. If you search for google.com, ask.com or msn.com for terms: link exchange or link trade you will be able to find some good ones. Here are few that I have found: linkmarket.net, linkexchagned.com and linkpartners.com.

This guide is licensed under the GNU Free Documentation License. It uses material from the Wikipedia.

Link campaigns are a form of online marketing and is also a method for search engine optimization. A business seeking to increase the number of visitors to its web site can ask its strategic partners, professional organizations, chambers of commerce, suppliers, and customers to add links from their web sites. Typically a link campaign involves mutual links back and forth between related sites.

Increasing the number of links to a site has two beneficial effects:

• Search engines such as Google judge the importance of a site by the number of other sites that link to it.
• The additional links result in visitors moving from the linking site to the target site.

When conducting a link campaign, the essentials steps are to identify potential link partners, request the links, and specify the link text. The value of a link depends on the traffic and reputation of the linking site, and the relevancy of its content to the target site’s content. Off topic links are generally not useful because they tend to upset visitors, and search engines may view them as link spam.

Link farms are web sites set up solely for the purpose of exchanging links. These sites are viewed dimly by search engines, and Google specifically advises webmasters not to participate in link farms:

“Linking schemes will often do a site more harm than good.”

This guide is licensed under the GNU Free Documentation License. It uses material from the Wikipedia.

Keyword stuffing is considered to be an unethical Search engine optimization (SEO) technique. Keyword stuffing occurs when a web page is loaded with keywords in the meta tags or in content. The repetition of words in meta tags, may explain why many search engines no longer use these tags.

Keyword stuffing is used is to obtain maximum search engine ranking and visibility for particular phrases. A word that is repeated too often may raise a red flag to search engines.

Hiding text out of view of the visitor is done in many different ways. Text colored to blend with the background, CSS “Z” positioning to place text “behind” an image – and therefore out of view of the visitor – and CSS absolute positioning to have the text positioned several feet away from the page center, are all common techniques. As of 2005, some of these invisible text techniques can be detected by major search engines.

“Noscript” tags are another way to place hidden content within a page. While they are a valid optimization method for displaying an alternative representation of scripted content, they may be abused, since search engines may index content that is invisible to most visitors.

Inserted text sometimes includes words that are frequently searched (such as “sex”) even if those terms bear little connection to the content of a page, in order to attract traffic to advert-driven pages.

Links

• Google Guidelines
• Yahoo! Guidelines

This guide is licensed under the GNU Free Documentation License. It uses material from the Wikipedia.

Keyword density is the percentage of words on a web page that match a specified set of keywords. In the context of search engine optimization keyword density can be used as a factor in determining whether a web page is relevant to a specified keyword or keyword phrase. Due to the ease of managing keyword density, search engines usually implement other measures of relevancy to prevent unscrupulous webmasters from creating search spam through practices such as keyword stuffing.

There is also much confusion between the notions of similarity and relevance. These are not the same thing. It has often been said by many companies doing topic clustering, document filtering, and other such applications that their algorithms function by grouping relevant documents together. What is actually meant is that the algorithms are grouping similar documents together. Two (or more) documents are never relevant to each other. They may be similar to each other, but they are only ever relevant to a user’s information need. If there is no user information need, there is no relevance.

The cluster hypothesis in information retrieval says that two documents that are similar to each other have a high likelihood of being relevant to the same information need. Documents by themselves, however, are never relevant to each other. Relevance is defined in terms of a user’s information need.

This guide is licensed under the GNU Free Documentation License. It uses material from the Wikipedia.

In the simplest case, relevance can be calculated by examining how many times a query term appears in a document (term frequency), possibly combined with how discriminative that query term is across the searched collection (often called Term Frequency-Inverse Document Frequency).

Since search engines and other businesses rely upon the accuracy of their results, many additional, more complex algorithms have been developed to estimate result relevance. Many of these algorithms, particularly those used by search engines, are hidden to the public, as a user that knows the details of a search algorithm can artificially boost his own content’s ranking.

Relevance calculation is often misinterpreted by the press. For example, it has often been said that when Google burst onto the scene it was miles ahead of its competitors because it, unlike anyone else, ranked web pages by relevance. This is not true since everyone ranks by relevance. It is just that Google had come up with a fairly new way of estimating relevance, namely PageRank. But even search engines that only use TFIDF rank by relevance.

This guide is licensed under the GNU Free Documentation License. It uses material from the Wikipedia.