Search engine marketing (SEM) is Internet marketing that promotes websites in search engine result pages (SERPs). When a company uses SEM to find prospects, it is typically buying paid search listings through Google AdWords, Yahoo Search Marketing and Microsoft adCenter. In 2022, American advertisers spent 616 billion dollars on search engine marketing. SEM is the fastest growing form of advertising for 2 simple reasons. It is affordable for businesses small and large, and it works!