Most commercial search engines provide a mechanism to determine the number of backlinks they have recorded to a particular web page. For example, Google can be searched using link: wikipedia.org (or link: en.wikipedia.org) to find the number of pages on the Web pointing to http://wikipedia.org/.

Yahoo!’s Site Explorer is a method of obtaining the number of backlinks on a site.

On the World Wide Web, a link farm is any group of web sites that all hyperlink to every other site 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 or spamexing). Other link exchange systems are designed to allow individual websites to selectively exchange links with other relevant websites and are not considered a form of spamdexing.

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 million 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 primarily for 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.

Anchor text is weighted (ranked) highly in search engine algorithms, because the linked text is usually relevant to the landing page. The objective of search engines is to provide highly relevant search results; this is where anchor text helps, as the tendency is, more often than not, to hyperlink words relevant to the landing page.

Webmasters may use anchor text to procure high results in search engine results pages. Google's Webmaster Tools facilitate this optimization by letting website owners view the most common words in anchor text linking to their site.

In the past, Google bombing has been possible through anchor text manipulation; however, in January, 2007, Google announced it had updated its algorithm to minimize the impact of Google bombs.

Web content is the textual, visual or aural content that is encountered as part of the user experience on websites. It may include, among other things: text, images, sounds, videos and animations.

In "Information Architecture for the World Wide Web" (second edition, page 219), Lou Rosenfeld and Peter Morville write, "We define content broadly as 'the stuff in your Web site.' This may include documents, data, applications, e-services, images, audio and video files, personal Web pages, archived e-mail messages, and more. And we include future stuff as well as present stuff."

A current meme when organizing or building a website is the catchwords "Content is King" (although Andrew Odlyzko in "Content is Not King" argues otherwise). What is meant by the term "content" is written text in plain vanilla HTML or a variant that produces good clean text that can be indexed with ease by a search engine.

This argument is valid to a greater extent, not because people will find it interesting and useful, or a good enough description to buy the product online, but because search engines can index text easily and if the information is close to what a searcher is seeking can be delivered as a site for the seeker of information. Textual information is therefore "king" online to aid the rather raw search tools to operate rather than actually to be impelling for people when seeking 

Creative and keyword rich content can play an important role in boosting sales and profits for home-based businesses that rely on web sites for customer acquisitions. Developing strategic marketing articles that both attract better search engines results and increased customers will drive the profits and awareness of your online site. Indeed, keyword rich content that provides useful information to prospective clients is an essential element of search engine optimization strategies for small business websites.

The first step to creating keyword rich content for your web site is to develop an understanding of what it actually is. The term ‘keyword’ refers to the words a potential customer uses in a search engine to find a particular product or service. For example, a client seeking a new job may search for “professional resumes” or “marketing resumes.” Thus, keyword rich content is text that makes frequent, strategic use of a specific search term.

In the past, many content makers focused more on repeating their keywords throughout their keyword rich content, rather than on providing quality information to web browsers. They wrote articles that served search engine spiders rather than customers. This strategy resulted in the proliferation of poorly written content that provided little or no useful information to end consumers.

While this strategy is still used by some online strategists, most internet companies changed their content development after realizing that search engine spiders rarely purchase peddled goods. Therefore, the vast majority of keyword rich content articles are actually designed to serve a higher intellectual purpose. Indeed, modern internet users are not impressed by keyword rich content that is riddled with grammatical errors and provides little useful information. Poor content will make them doubt the quality of your services.

Today, those interested in building successful web sites use quality keyword rich content. Rather than just focusing on how many times they can repeat a given phrase in a body of text, the writers of these articles provide well-written material with solid information to benefit the reader.

In preparing to write keyword rich content for your site, you must first determine what words a potential client will most likely use when searching the web. Next, write creative, copy for each phrase that incorporates not only information about your products and services, but also tips for making the best use of your retailed goods. For example, if your site sells tea, in addition to content describing your products and why customers should purchase from you, include information on how to make a perfect pot of tea or the latest research about how green tea aids in improving one’s overall health. Most importantly, make your keyword rich content engaging and useful. Connect with your readers and earn their interest and trust.

Keyword rich content that both attracts spiders and impresses people is an essential part of the overall success of your web site. Investing time and effort to create high quality website articles is now a critical component of all major online marketing strategies. Besides improving the overall popularity of your online business within the search engine caches, creative article writing can help to establish your business as an expert voice, a trusted advisor and a premium site that offers more than just direct selling tactics.