Search engine marketing (SEM)

From Wikipedia, the free encyclopedia

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). According to the Search Engine Marketing Professionals Organization, SEM methods include: search engine optimization (or SEO), paid placement, and paid inclusion. Other sources, including the New York Times, define SEM as the practice of buying paid search listings.

Market structure

In 2006, North American advertisers spent US$9.4 billion on search engine marketing, a 62% increase over the prior year and a 750% increase over the 2002 year. The largest SEM vendors are Google AdWords, Yahoo! Search Marketing and Microsoft adCenter. As of 2006, SEM was growing much faster than traditional advertising.

History

As the number of sites on the Web increased in the mid-to-late 90s, search engines started appearing to help people find information quickly. Search engines developed business models to finance their services, such as pay per click programs offered by Open Text in 1996 and then Goto.com in 1998. Goto.com later changed its name to Overture in 2001, and was purchased by Yahoo! in 2003, and now offers paid search opportunities for advertisers through Yahoo! Search Marketing. Google also began to offer advertisements on search results pages in 2000 through the Google AdWords program. By 2007 pay-per-click programs proved to be primary money-makers for search engines.

Search engine optimization consultants expanded their offerings to help businesses learn about and use the advertising opportunites offered by search engines, and new agencies focusing primarily upon marketing and advertising through search engines emerged. The term "Search Engine Marketing" was proposed by Danny Sullivan in 2001 to cover the spectrum of activities involved in performing SEO, managing paid listings at the search engines, submitting sites to directories, and developing online marketing strategies for businesses, organizations, and individuals. In 2007 Search Engine Marketing is stronger than ever with SEM Budgets up 750% as shown with stats dating back to 2002 vs 2006.[citation needed]

Ethical questions

Paid search advertising hasn't been without controversy, and issues around how many search engines present advertising on their pages of search result sets have been the target of a series of studies and reports by Consumer Reports WebWatch, from Consumers Union. The FTC also issued a letter in 2002 about the importance of disclosure of paid advertising on search engines, in response to a complaint from Commercial Alert, a consumer advocacy group with ties to Ralph Nader.

Search Engines - Theory

Search engines provide an interface to a group of items that enables users to specify criteria about an item of interest and have the engine find the matching items. The criteria are referred to as a search query. In the case of text search engines, the search query is typically expressed as a set of words that identify the desired concept that one or more documents may contain.[1]

There are several styles of search query syntax that vary in strictness. Where as some text search engines require users to enter two or three words separated by white space, other search engines may enable users to specify entire documents, pictures, sounds, and various forms of natural language. Some search engines apply improvements to search queries to increase the likelihood of providing a quality set of items through a process known as query expansion.

index-based search engineThe list of items that meet the criteria specified by the query is typically sorted, or ranked, in some regard so as to place the most relevant items first. Ranking items by relevance (from highest to lowest) reduces the time required to find the desired information. Probabilistic search engines rank items based on measures of similarity and sometimes popularity or authority. Boolean search engines typically only return items which match exactly without regard to order.

To provide a set of matching items quickly, a search engine will typically collect metadata about the group of items under consideration beforehand through a process referred to as indexing. The index typically requires a smaller amount of computer storage, and provides a basis for the search engine to calculate item relevance. The search engine may store of copy of each item in a cache so that users can see the state of the item at the time it was indexed or for archive purposes or to make repetitive processes work more efficiently and quickly.

Notably, some search engines do not store an index. Crawler, or spider type search engines may collect and assess items at the time of the search query. Meta search engines simply reuse the index or results of one or more other search engines.

source: http://en.wikipedia.org/wiki/Search_engines

Number - Definition

A number is an abstract idea used in counting and measuring. A symbol which represents a number is called a numeral, but in common usage the word number is used for both the idea and the symbol. In addition to their use in counting and measuring, numerals are often used for labels (telephone numbers), for ordering (serial numbers), and for codes (ISBNs). In mathematics, the definition of number has been extended over the years to include such numbers as zero, negative numbers, rational numbers, irrational numbers, and complex numbers.

Certain procedures which input one or more numbers and output a number are called numerical operations. Unary operations input a single number and output a single number. For example, the successor operation adds one to an integer: the successor of 4 is 5. More common are binary operations which input two numbers and output a single number. Examples of binary operations include addition, subtraction, multiplication, division, and exponentiation. The study of numerical operations is called arithmetic.

The branch of mathematics that studies abstract number systems such as groups, rings and fields is called abstract algebra.

Source: http://en.wikipedia.org/wiki/Number

Definition

Statistics is a mathematical science pertaining to the collection, analysis, interpretation or explanation, and presentation of data. It is applicable to a wide variety of academic disciplines, from the physical and social sciences to the humanities. Statistics are also used for making informed decisions.

Statistical methods can be used to summarize or describe a collection of data; this is called descriptive statistics. In addition, patterns in the data may be modeled in a way that accounts for randomness and uncertainty in the observations, and then used to draw inferences about the process or population being studied; this is called inferential statistics. Both descriptive and inferential statistics comprise applied statistics. There is also a discipline called mathematical statistics, which is concerned with the theoretical basis of the subject.

source : http://en.wikipedia.org/wiki/Statistics