During the initial days of Online advertising, the first advertiser chose where and when his ads will be displayed without considering the context of the webpage. This is similar to how newspaper advertisements work. That was Until Google AdSense was introduced. AdSense included the page’s overall context in deciding which type of ad campaigns will run on that page. For example, if a web surfer goes to a page about mobile phones, then Google AdSense may serve advertisements about mobile phones because the ads are relatively more relevant to what the user is interested in. However, there are times when contextual advertising does not work effectively, mostly in the case of satirical or sarcastic context.