Search algorithms & popularity factors: link, social, click, blog, industry. Since modern search engines are concerned with popularity and not direct relevancy, & big firms up the price of text link buying beyond affordability...
A. Balmin, V. Hristidis, und Y. Papakonstantinou. VLDB '04: Proceedings of the Thirtieth international conference on Very large data bases, Seite 564--575. VLDB Endowment, (2004)
A. Hotho, R. Jäschke, C. Schmitz, und G. Stumme. The Semantic Web: Research and Applications, Volume 4011 von Lecture Notes in Computer Science, Seite 411--426. Berlin/Heidelberg, Springer, (Juni 2006)
R. Jin, H. Valizadegan, und H. Li. WWW '08: Proceeding of the 17th international conference on World Wide Web, Seite 397--406. New York, NY, USA, ACM, (2008)
S. Bao, G. Xue, X. Wu, Y. Yu, B. Fei, und Z. Su. WWW '07: Proceedings of the 16th international conference on World Wide Web, Seite 501--510. New York, NY, USA, ACM, (2007)