Keyword advertising refers to any advertise that is linked with particular words or phrases. The other name is also Pay Per Click or Cost Per Attention. It is a form of advertising which focuses on a special keyword or text on a web page or any media for displaying ads. This works by finding out what the user wants from the web page. There are two types of keywords advertisements. They are static keywords advertisement and dynamic keyword advertisement. The former type was being used before but the latter form is being used extensively now a days. In dynamic keywords advertising, the advertisements change with the contents of the page. This would increase the probability of clicks on the ads. For instance, if the user is viewing information of food, the ads appearing on the context advertising section would display links related to food companies and types, classification. The keywords are discovered by mining the data on the content page. Search engines use the keywords provided by the user for the search. This would optimize the search criteria and speed up the process. Google AdWords is the most well-known form of keyword advertising. Google displays search ads specifically targeted to the word(s) typed into a search box.