Search Engine Marketing (SEM), involves promoting a Web site using search engines by using a number of techniques. One of these ways is to improve the site's organic ranking through search engine marketing. Another is by buying pay-per-click (PPC) ads with search engines. These ads are based on selected keywords and then are displayed on search engine results pages when the relevant keywords are used by searchers. They may also appear on other Web sites whose content includes the keywords specified. Still another type of search engine marketing involves link building. Getting and creating inbound links to a website from other relevantsites is a way of increasing awareness of the site and increasing organic rankings in the search engines.