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...
K. Sonawane, B. Wagh, M. Shelar, and N. Yeole. International Journal on Recent and Innovation Trends in Computing and Communication, 3 (1):
280--283(January 2015)
K. Sonawane, B. Wagh, M. Shelar, and N. Yeole. International Journal on Recent and Innovation Trends in Computing and Communication, 3 (1):
280--283(January 2015)