<P> Apart from that when a visitor doesn't click on the ad in a go through time (a minimum time a user must click on the ad) the ad is automatically changed to next relevant ad showing the option below of going back to the previous ad . </P> <P> Contextual ads and its dot effect are less irritable than traditional advertising . That is why it influences user more effectively . It shows user area of interest thus increasing the chance of receiving a response . </P> <P> Google AdSense was the first major contextual advertising network . It works by providing webmasters with JavaScript code that, when inserted into webpages, displays relevant advertisements from the Google inventory of advertisers . The relevance is calculated by a separate Google bot, Mediabot, that indexes the content of a webpage . Recent technology / service providers have emerged with more sophisticated systems that use language - independent proximity pattern matching algorithm to increase matching accuracy . </P> <P> Media.net is the other major contextual ad network competing with Google Adsense . </P>

Google's adsense advertising is a form of contextual advertising