In.his.iagram, if each bubble represents a website, programs sometimes called spiders examine which sites link to which other sites, with arrows representing these links. The leading search engines, such as goggle, Ming and Yahoo! Depending on their history of previous searches, goggle crafted results for logged in users. 27 In 2008, Bruce Clay said that “ranking is dead” because of personalized search . There's a good chance we can help. Not every page is indexed by the search engines. Site owners started to recognize the value of having their sites highly ranked and visible in search engine results, creating an opportunity for both white hat and black hat CEO practitioners. This had an impact on Dell's search presence and increased their organic rankings, traffic, and revenue. The search engines attempt to minimize the effect of the latter, among them spamdexing . One black hat technique uses text that is hidden, either as text coloured similar to the background, in an invisible did, or positioned off screen.