Spamdex
Spamdexing is any of various methods to manipulate the relevancy or prominence of resources indexed by a search engine.
The rise of spamdexing in the mid-1990s made the leading search engines of the time less useful.
Spamdexing is usually done in a manner inconsistent with the purpose of the indexing system. Search engines use a variety of algorithms to determine relevancy ranking. Some of these include determining whether the search term appears in the META keywords tag, 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.
The earliest known reference to the term spamdexing is by Eric Convey in his article "Porn sneaks way back on Web," The Boston Herald.
Read the wikipedia article on Spamdex for a complete overview of all different smapping techniques.
