The document discusses search engine marketing (SEM) and pay-per-click (PPC) advertising. It provides a history of SEM, noting the emergence of paid search programs in the late 1990s. Various SEM techniques are outlined, including paid inclusion and PPC advertising. PPC advertising is discussed in further detail, including the history of PPC beginning in 1998, the two main types of PPC (bid-based and flat rate), and some of the top PPC search engines. Ethical issues regarding paid search advertising are also briefly mentioned.