Spamdexing 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. More at Wikipedia
Adversarial information retrieval - Adversarial information retrieval is a topic in information retrieval that addresses tasks such as gathering, indexing, filtering, retrieving and ranking information from collections wherein a s...
Parasite hosting - Parasite hosting is the process of hosting a site on someone else's server without their consent, generally for the purpose of search engine benefit.
TrustRank - TrustRank is a link analysis technique described in a paper by Stanford University and Yahoo! researchers for semi-automatically separating useful webpages from spam.