Banner ads
A banner ad is one of the main forms of advertising inventory on a website. The IAB has defined standard formats for banner ads, as well as skyscrapers (ads that appear on the side of a web page), pop-ups and a growing number of rich media formats (ads that incorporate video or some form of interactivity).
Behavioural targeting
Behavioural targeting is where advertisers refine their campaigns by concentrating on specific user segments in the network. Cookies (small pieces of information stored on users' computers) track individuals' surfing habits after they've left a website. An ad network uses this information to segment users into audiences based on sites visited, searches made, pages viewed and other actions.
Blind network
Advertisers using blind networks don't have any control over where their ads will appear, so inventory is cheaper to purchase as a result. For publishers, blind networks offer the opportunity to sell excess inventory without jeopardising any direct relationships they may have with advertisers. Blind networks are also known as undisclosed networks.
CPA (cost per action)
Another metric used by publishers. Where CPA is concerned, advertisers only pay if a web user takes an action - for example, makes a purchase, clicks on a search listing (cost per click) or registers (cost per registration). Brendan Condon, managing director of Platform-A International, says: "The metric used depends on whether the advertiser is looking for branding, in which case they'd use CPM, or performance-based results, when they would use CPA and only pay for results."
CPM (cost per thousand)
CPM is a metric publishers use to charge for inventory and stands for the cost per thousand page impressions served to a web user. The "M" in CPM comes from "mille", the Latin word for "thousand".
IASH (Internet Advertising Sales House)
The UK regulatory body for online ad networks, which operates under the IAB (Internet Advertising Bureau). Richard Sharp, UK managing director of ValueClick Media, says: "Many people will say they are IASH-accredited but they are only an IASH member if they have passed an audit within the last six months." In July, 24/7 Real Media was suspended from IASH for failing to take part in such an audit.
Online ad exchange
The online ad network industry consists of third-party sales houses (such as Ad2One and Woot!Media, which sell inventory on specific sites), online ad networks (such as ValueClick, which pool and sell advertising inventory across multiple sites) and online ad exchanges. Hugo Drayton, UK chief executive of ad exchange Phorm, describes ad exchanges as marketplaces that "bring advertisers and publishers together, without the need for salespeople".
Post-impression tracking
This is technology that monitors a user's activity from the point an ad is viewed. Paul Smith, joint managing director of Eyeconomy, explains: "If the user subsequently converts into a sale on the relevant website, the conversion is assigned to the specific ad in question." Advertisers will analyse post-impressions and post-clicks (the actions taken by a user after clicking on an ad) to assess the success of a campaign.
Re-targeting
This form of targeting gives advertisers a second chance to reach a user who has demonstrated interest in an advertisement but has not acted on it. Mike James, managing director of Adconion UK, says: "If someone clicks on an ad but doesn't get to the conversion page, we can re-target that user the next time we see them on our network with different creative."
Roadblock
"A roadblock is when an advertiser buys all the ads on a web page," explains Austen Kay, managing director of Woot!Media, which represents cult sites such as Holy Moly.
RON (run of network)
Run of network delivers an ad to all available inventory on an ad network, while Run of channel (ROC) gives advertisers access to any inventory in a particular channel on the network. "For example, if you did ROC, you could be more contextually relevant and target a car ad at people who are in the cars channel," points out Linus Gregoriadis, head of research at E-consultancy. "By contrast, with RON your ad could be going to any Tom, Dick or Harry."
ROS (run of site)
"This is a media buy for marketers who want to target consumers on a specific website," explains Paul Thompson, Yahoo UK head of planning and strategy. "When an advertiser buys run of site, there is usually no guarantee which pages or section the ads will appear on or where they will be placed, but the advertiser is assured of the general environment."