Search engine marketing (SEM), is a method of online marketing in which the goal is to promote websites by increasing the websites visibility and thus volume of traffic in the search engines. SEM is a term commonly used when referring to paid placement and paid inclusion advertising but also mentioned in terms of SEO by some.

Search engine marketing however is not limited to just paid advertising, it also encompasses the practice of marketing in its true sense, knowing how to promote products and services and attract the customers attention and prompt them to action to purchase, to this end online marketers need to be equipment with a thorough understanding of statistical analysis, to know what converts to sales, as well as a websites hot and cold spots.

Above all search engine marketing today requires the management of paid listings, site submissions and preparing online marketing strategies for businesses, the broadening of products offered to clients and the responsibilities of SEM has seen a new market develop where agencies seek to focus on this ever increasing and hugely cashed-up, paid listing market.

With the continual, rapid growth and pace of the internet marketplace, SEM is now growing at a pace with exceeds traditional advertising, figures show the advertising spend for North America along has well exceeded USD$20.0 billion with the majority of that of that market in the grasp of the big search engine giants Google, Yahoo and Microsoft.