Search engine ads are advertisements that appear when the user starts a search query with a certain keyword on Google or another search engine. On the following page with the found search results, the ads are usually displayed at the top or bottom of the page. As an advertiser, you bid for keywords that you want to associate with your website. A keyword research can be very useful for this. Once someone clicks on your ad, as an advertiser you pay an amount based on the traffic generated by the click.