A Taxonomy of Hyperlink Hiding Techniques

TL;DR

This paper presents a detailed taxonomy of hyperlink hiding techniques used mainly for black industry profits, analyzes their prevalence on Chinese websites, and examines search engine responses to such spam.

Contribution

It provides the first comprehensive taxonomy of hyperlink hiding techniques and evaluates their widespread use and impact on search engine rankings.

Findings

Link hiding techniques are highly prevalent on Chinese websites.

Google's PageRank is affected by hidden link spam.

More measures are needed to combat link hiding spam.

Abstract

Hidden links are designed solely for search engines rather than visitors. To get high search engine rankings, link hiding techniques are usually used for the profitability of black industries, such as illicit game servers, false medical services, illegal gambling, and less attractive high-profit industry, etc. This paper investigates hyperlink hiding techniques on the Web, and gives a detailed taxonomy. We believe the taxonomy can help develop appropriate countermeasures. Study on 5,583,451 Chinese sites' home pages indicate that link hidden techniques are very prevalent on the Web. We also tried to explore the attitude of Google towards link hiding spam by analyzing the PageRank values of relative links. The results show that more should be done to punish the hidden link spam.