Rules of SEM: Search Marketing Campaign law provides a way to define the guidelines for publishers using different keywords SEM [search engine marketing] campaigns. In addition to the properties of a connection to a common keyword in the search marketing campaign allows you to reference specific sections for specific terms and conditions. In short, this means that some advertisers do not advertise on a few keywords or key phrases of your search campaigns, so you'll need to set the titles of the ads on different or related content.