Bid - The amount that an advertiser is willing to pay for a click on a specific keyword.
Budget - The amount of money that an advertiser sets aside for an advertising campaign. Different publishers allow for advertisers to set daily, weekly or monthly budgets.
Clickthrough Rate (CTR) - The percentage of clicks on a link. This is usually a percentage based on the total number of clicks divided by the number of impressions that an advertisement has received.
Conversion Rate - The relationship between visitors to a web site and actions considered to be a "conversion", such as a sale or request to receive more information: the percentage of people whose clicks have resulted in a sale or desired action in relation to the total number of clicks on an advertisement.
Cost Per Click (CPC) - The cost or cost-equivalent paid per click-through to an advertiser's website.
Cost Per Thousand (CPM) - The amount an advertiser pays for one thousand advertisement impressions, regardless of the consumer's subsequent actions.
Delisting - The removal of an ad listing as a result of inaction or poor performance.
GeoTargetting - An advertisement targeted at a specific geographical region, area or location.
Impressions - The number of times an advertisement is viewed by web surfers.
Keywords - Search terms or phrases that are related to an advertisement or ad copy.
Landing Page - The specific web page that a visitor ultimately reaches after clicking an advertisement. Often, this page is optimized for a specific keyword term or phrase.
Linking Text or Anchor Text - The text that is contained within a link.
Pay Per Click (PPC) - Advertising model in which advertisers pay for click-throughs to their website. Ads are served based on keywords or themes.
Rank - How well a particular web page or web site is listed in a search engine or advertising results.
Return On Investment (ROI) - The percentage of profit that results in a marketing or advertising campaign. Naturally, advertisers want the amount of money made to exceed the money spent.