Search Engine Marketing Definition

Search Engine Marketing (SEM) also known as keyword marketing is defined by Search Engine Marketing Professionals Organization(SEMPO) as a combination of  Search Engine Optimization(SEO), paid placements, also known as Pay Per Click(PPC)  and paid inclusion.

It is a form of Internet Marketing that is used to improve the placement of a website in Search Engine Result Pages (SERPs).   As SEM has a high hit rate with a low cost per hit, it is the most popular form of internet marketing for small and medium-sized enterprises. Search Engine Optimization (SEO) is a process used to increase the number of visitors to a website by improving the ranking within a search engine. There are hundreds of different variables that have to be considered, strategically applied and monitored in order to influence rankings. The results of SEO on a page are seen as answers to a search as opposed to advertising on a page which is achieved by PPC

Pay per click (PPC) is the most common form of SEM. Website owners choose keywords and then bid an amount they are willing to pay for every click on that keyword – the higher the bid the higher the placement. PPC is slightly different for each search engine but the basics are the same. It is seen largely as advertising and has a much lower hit rate than organic searches achieved through SEO. PPC ads are often referred to as “sponsored links” or “sponsored ads”.

Search Engine Result Pages(SERPs) are pages listing the results of a particular keyword query. This is usually a list of web pages showing the titles, a link to the page, and a brief description of which  keywords have matched your search to the page. SERPs of major search engines usually include different types of listings: organic search listings, sponsored listings, images, maps, definitions, or suggested search refinements. The major search engines also offer different types of searches – i.e. image, news, and blog search.
These ads are called a "Sponsored link" or "sponsored ads" and appear next to, and sometimes, above the natural or organic results on search engine results pages.

Paid Inclusion is the system whereby a webmaster pays a search engine company to have their page included in a search index. Paid inclusion is provided by most search engines, but not Google.
The fee is usually payable annually and provides both a filter against superfluous submissions and a revenue generator. Some detractors of paid inclusion allege that it causes searches to return results based more on the economic standing of the interests of a web site, and less on the relevancy of that site to end-users.
Paid inclusion can be of value in cases where pages are dynamically generated and frequently modified. Paid inclusion could be viewed as a tool of search engine optimization, since it can be used to test different approaches to improving ranking, with the results often available in a couple of days, instead of weeks or months. This information can then be used to optimize other web pages.