A piece of code containing the agreed-upon terms (negotiated pricing, for example) between an advertiser and publisher that allows the advertiser to access the publisher’s inventory.

Identifier attached to a person’s internet browser to track the sites he or she visits.

An online marketplace for advertisers to buy and sell inventory, often through real-time auctions. Top players include Google’s AdX, Yahoo’s Right Media, Facebook Exchange and AppNexus.

When a company knowingly serves ads that no one will actually see as a way to drive “views” and revenue. For example, a website can use bots to automatically refresh is pages in order to register a high number of page views and appear more attractive as an inventory source on ad exchanges.

A company that deals with advertisers and publishers to manually buy and sell ads across the web. Top players include Google Display Network, AOL’s Advertising.com, Millennial Media.

A company whose technology relays an ad buy to a website and reports on how it performed. Top players include Google’s DoubleClick for Publishers, Facebook’s Atlas, Sizmek

A division within an ad agency focused on buying ads and using technology. Top players include Omnicom’s Accuen, WPP’s Xaxis, Publicis Groupe’s Vivaki, Interpublic Group’s Cadreon.

Sometimes called “look-alike modeling,” a process that takes a known audience segment and catalogs various shared characteristics that can be used to target people who bear similarities and are therefore likely to become customers. For example, Facebook identifies the top interests of people who “like” Coca Cola’s Facebook page and creates an audie [..]

Showing ads to people based on the types of sites they visit. For example, targeting people who visit ESPN.com and the New York Post’s site with ads for New York sports teams.

A company that provides technology for media buyers to purchase ad placements, typically via bids in exchanges’ real-time auctions. Top players include MediaMath, Turn, Google’s DoubleClick Bid Manager.