An API, or Application Programming Interface, enables software applications to communicate with each other. Just as a user interface allows a person to interact with a software application, an API allows a program to interact with another piece of software.


CPC, or Cost Per Click, refers to the amount spent every time a user clicks on a keyword advertisement.


CPM refers to the cost for one thousand impressions of an ad unit, such as a banner advertisement. The term CPM typically does not apply to PPC advertising mechanisms.


CTR, or Click Through Rate, is the fraction of users who click on a keyword advertisement to those that view that advertisement (an impression). CTR is usually expressed as a percentage.


An impressions is the number of times a particular keyword ad is shown.


Search queries are referred to as keywords when used targeted by SEO and search engine advertising. Keywords may be singles words or phrases.


Link-building is the practice of obtaining links from external web sites to your own to improve both direct referrals (people clicking on the links) and search engine ranking.

Page Rank

Page Rank (often denoted PR) is a quantity defined by Google that provides a rough estimate of a web page's importance. Many factors that influence Page Rank, and it is a poor indicator of how well a page ranks for particular keywords.


PPC stands for Pay-Per-Click. It refers to online marketing methods in which the advertiser is pays each time someone clicks on their ad. Usually PPC ad programs do not charge for impressions.

Reciprocal Linking

Reciprocal linking, or link-trading, is the creation of a link from your site to another in exchange for a link back from that site to yours. Links often factor into search engine ranking.


ROAS stands for Return On Advertising Spending and represents the dollars earned per dollars spent on the corresponding advertising. To determine ROAS, divide revenue derived from the ad source by the cost of that ad source. Values less than one indicate that less revenue is generated than is spent on the advertising. A full cost/benefit analysis requires consideration of profit, instead of revenue, versus advertising spending.

Search Engine Advertising

Most search engines show ads alongside search results. The search query determines which ads are shown.

Search Engine Ranking

Search Engine Ranking refers to the position at which a particular site appears in the results of a search engine query. A site is said to have a high ranking when it appears at or near the top of the list of results. Just to confuse things, results are typically numbered starting at 1 and increasing down the list of results, thus a "higher ranking" corresponds to a lower number, 1 being ideal.


Search Engine Marketing, or SEM, refers to a variety of tasks that seek to increase the number of people visiting a website that come from search engines. The two primary techniques are SEO and search engine advertising.


SEO, or Search Engine Optimization, refers to a set of practices that increase the search engine ranking of a web page. Most SEO techniques involve changes to the page such as increased use of keywords in the page title and copy. SEO often includes link-building.


Search engine spiders are software applications used by search engines to index web pages. They "spider" the web by following links from one page to another.

Email this page Print this page Bookmark this page