Spamdexing

Spamdexing (also known as search spam, search engine spam or web spam) involves a number of methods, such as repeating unrelated phrases, to manipulate the relevancy or prominence of resources indexed by a search engine, in a manner inconsistent with the purpose of the indexing system. Some consider it to be a part of search engine optimization, though there are many search engine optimization methods that improve the quality and appearance of the content of websites and serve content useful to many users.

Search engines use a variety of algorithms to determine relevancy ranking. Some of these include determining whether the search term appears in the metatags, others whether the search term appears in the body text or URL of a web page. Many search engines check for instances of spamdexing and will remove suspect pages from their indexes. Also, people working for a search-engine organization can quickly block the results-listing from entire websites that use spamdexing, perhaps alerted by user complaints of false matches. The rise of spamdexing in the mid-1990s made the leading search engines of the time less useful.

The success of Google at both producing better search results and combating keyword spamming, through its reputation-based PageRank link analysis system, helped it become the dominant search site late in the 1990s.