Search engine marketing, or SEM, is a form of Internet
marketing that seeks to promote websites by increasing their visibility in
search engine result pages (SERPs) through the use of search engine
optimization, paid placement, contextual advertising, and paid inclusion. Usage
of the term "search engine marketing" has been inconsistent. The trade
association Search Engine Marketing Professional Organization (SEMPO) includes
search engine optimization (SEO), and SEO is also included in the industry
definitions of SEM by Forrester Research, eMarketer, Search Engine Watch, and
industry expert Danny Sullivan. However, the New York Times restricts the
definition to 'the practice of buying paid search listings'.