Search engine marketing (SEM) is a form of Internet marketing that involves the promotion of websites by increasing their visibility in search engine results pages (SERPs) primarily through paid advertising. SEM may incorporate search engine optimization (SEO), which adjusts or rewrites website content and site architecture to achieve a higher ranking in search engine results pages to enhance pay per click (PPC) listings.
In the parlance of digital marketing, advertisers are commonly referred to as sources, while members of the targeted ads are commonly called receivers. Sources frequently target highly specific, well-defined receivers. For example, after extending the late-night hours of many of its locations, McDonald's needed to get the word out. It targeted shift workers and travelers with digital ads, because the company knew that these people made up a large segment of its late night business. McDonald's encouraged them to download a new Restaurant Finder app, targeting them with ads placed at ATMs and gas stations, as well as on websites that it new its customers frequented at night.