A link farm is a network of sites that link to other sites for the sole purpose of increasing link popularity. This is when a website gets hundreds of links to unrelated sites in exchange for reciprocal links. This is termed as spamming and any website who relates to link farms is penalized by removal from a search engine’s index. Backgrounder on Link Farms Link farms were originally developed by search engine optimizers to take advantage of the Inktomi search engine’s dependence on link popularity. It was targeted for manipulation with the use of link farms because of the fact that it was used by a number of independent but popular search engines. The most popular search engines during that time – Yahoo! also used Inktomi results as a supplement to its own directory search feature. Link farms facilitated the stabilization of listings for online business websites having few natural links from more stable sites. Link popularity is used by most search engines to come up with a ranking order for search results. However, at the time link farms came to be, the Inktomi engine was maintaining two indexes. The primary index produced search results that are limited to about 100,000,000 listings thus pages with few inbound links fell out of the index on a regular basis. While the handling of link farm exchange was informal at the start, several service companies were eventually founded to handle automated registration, categorization and link page updates to member websites. The coming of the Google search engine paved the way for the use of a link weighting scheme called PageRank. The PageRank algorithm assigns more weight to links that it determines as more valuable than others. Link farming was used to help member pages to increase their PageRank. This soon became the subject of manipulation by unscrupulous webmasters who continue to receive inbound linkage but found ways to hide outbound links if not totally avoid posting any link at all to their sites. There came a need for link farm managers to implement quality controls and require member compliance to rules that were installed to ensure fairness. As a result, alternative link farm products emerged such as the link-finding software that identifies potential reciprocal link partners. This made possible the sending of template-based e-mails that offered link exchanges. Directory-like link pages were created for those websites intent on building link popularity as well as PageRank. The link farm movement was actively countered by search engines as they sought to identify specific attributes associated with link farms thus filtering those pages from indexing and search results. There were instances where entire domains had to be removed to prevent the potential influences of link farms on search results. Link farm-influenced crawling diminished as search engines increased their capacity to index more sites. It became unnecessary for link farms to help sites retain their positions in primary indexes. However, it remained a popular tool to increase PageRank or perceived equivalent values. The Inktomi technology has since become a part of Yahoo! while the term “Link Farm” is now widely considered as derogatory. There is still an ongoing debate as to the value of using PageRank in determining search results ranking. Reputable search engines are one in recommending that webmasters request for relevant links to their sites instead of participating in link farms. Sites that participate in link farms run the risk of having their search rankings penalized. Link Farm Spam Page or Not? Link farms usually refer to sites with an almost boundless list of links to other websites rather than links from page to page within a site. Relevancy to a site is not a major consideration in determining the links as the major purpose of linking is to get a high ranking among search engines. The provisions of good information to users cease to be the goal of these websites as they concentrate on attaining search popularity through the sheer number of links. When is a specific website said to be participating in a link farm? The current indication seems to be pointing at having not more than 100 links on a page as a safe measure. There are apprehensions of whether having numerous internal links will be interpreted as a link farm. A link farm is composed of a group of web pages that hyperlink to every other web page in the group. It can be manually created but is most often created through automated programs and services. It is sometimes called spamdexing as it is a form of spamming the index of a search engine. A term that is often associated with it is the “spaghetti code” which is a code with a complex and tangled control structure that uses unstructured branching constructs. The algorithmic principle that puts emphasis on the voting power of “authority sites” lies behind the manipulated processes of link farms. There is that assumption that related pages link to each other and authoritative pages tend to link to other authoritative pages. Conversely, being linked to spam sites or sites that use Black-Hat SEO degrades the reputation of any site. Association with poorly reputed sites affects a site’s search engine positioning as it stands to be categorized as an irrelevant site. As spammers continue to go around the valid purpose of linking, the value of reciprocal linking continue to decrease. Too many irrelevant links provide no value and can be seen as spam by human experts and search engines. A link directory with no clear, organized and distinct categories of links can be interpreted as a link farm especially if there are already more than 50 links on a page. TrustRank is used to counter the various techniques employed to achieve higher rankings than actually deserved in a search engine’s result. It uses a technique that manually identifies reputable seed pages and uses their link structure to discover other pages that are likely to be good as well. It aims to cut down on spam and deliver the real content that is desired by the searcher. There are a number of ways to ensure that a website’s link directory does not end up being categorized as another form of a link farm. Incorporating a link directory into a website has its own advantages but caution should be taken so as not to have too many outbound links on a page that dilutes its value. If a website’s links are very much varied and tend to be unrelated, they will need to be categorized to become relevant to each other. The use of clear, concise titles and descriptions for categories will help searchers (humans and search engines’ spiders alike) understand what a particular category is all about so that the measure of relevancy can out rightly be determined. It is not a requirement to agree to all link exchange requests especially if the requesting site cannot be considered a good representation of a site’s theme and values. It is highly recommended that regular follow-up on approved link exchanges is done to determine the status of the links and determine whether continued linkage with them is still acceptable. It is possible that although some links present themselves initially as good links have been banned, gone under, or moved. These are situations beyond anyone’s control so it is best for a website to work hard on keeping its links and contents relevant so as to bring continuous qualified traffic to itself. Link farms may be considered obsolete in a sense but it continuous to pop-up in different forms at present.