A web banner or banner ad is a form of advertising on the World Wide Web. This form of online advertising entails embedding an advertisement into a web page. It is intended to attract traffic to a website by linking them to the web site of the advertiser. The advertisement is constructed from an image (GIF, JPEG, PNG), JavaScript program or multimedia object employing technologies such as Java, Shockwave or Flash, often employing animation or sound to maximize presence. Images are usually in a high-aspect ratio shape. That is to say, either wide and short, or tall and narrow, hence the reference to banners. These images are usually placed on web pages that have interesting content, such as a newspaper article or an opinion piece.



The web banner is displayed when a web page that references the banner is loaded into a web browser. This event is known as an "impression". When the viewer clicks on the banner, the viewer is directed to the website advertised in the banner. This event is known as a "click through". In many cases, banners are delivered by a central ad server.

Many banner ads work on a click-through payback system. When the advertiser scans their logfiles and detects that a web user has visited the advertiser's site from the content site by clicking on the banner ad, the advertiser sends the content provider some small amount of money (usually around five to ten US cents). This payback system is often how the content provider is able to pay for the Internet access to supply the content in the first place.

Web banners function the same way as traditional advertisements are intended to function: notifying consumers of the product or service and presenting reasons why the consumer should choose the product in question, although web banners differ in that the results for advertisement campaigns may be monitored real-time and may be targeted to the viewer's interests.

Many web surfers regard these advertisements as highly annoying because they distract from a web page's actual content or waste bandwidth. Newer web browsers often include options to disable pop-ups or block images from selected websites. Another way of avoiding banners is to use a proxy server that blocks them, such as Privoxy.

History

The first clickable web ad (which later came to be known by the term "banner ad") was sold by Global Net Navigator (GNN) in 1993.

Founded by O'Reilly and Associates, Global Network Navigator (GNN) was the first commercially supported web publication and one of the very first web sites ever. Dale Dougherty was GNN's developer and publisher. O'Reilly and Associates sold GNN to AOL in 1995 and the site was discontinued a few years later.

The first web banner sold by HotWired, an important early pioneer in commercial web publishing started by Wired Magazine, was paid for by AT&T, and was put online on October 25, 1994.

HotWired was the first web site to sell banner ads in large quanities to a wide range of major corporate advertisers. Andrew Anker was HotWired's first CEO. Rick Boyce, a former media buyer with San Francisco advertising agency Hal Riney & Parnters, spearheaded the sales effort for the company. When HotWired was sold to Lycos, Boyce became its Vice President of Sales.

HotWired coined the term "banner ad" and was the first company to provide click through rate reports to its customers.

Standard sizes

The Interactive Advertising Bureau has released a set of sizes which it has designed to make ad sizing more predictable and better for both consumer and producer. It calls these web advertisements "interactive marketing units". The sizes are as follows (measurements in pixels):

Sizes for rectangular/pop-up ads

Medium Rectangle: 300 by 250

Square Pop-Up: 250 square

Vertical Rectangle: 240 by 400

Large Rectangle: 336 by 280

Rectangle: 180 by 150

Sizes for banner/button ads

Full Banner: 468 by 60

Half Banner: 234 by 60

Micro Button: 80 by 15

Micro Bar: 88 by 31

Button 1: 120 by 90

Button 2: 120 by 60

Vertical Banner: 120 by 240

Square Button: 125 square

Leaderboard: 728 by 90

Sizes for "skyscraper" ads

Wide Skyscraper: 160 by 600

Skyscraper: 120 by 600

Half Page Ad: 300 by 600

The IAB has also further standardized four of the sizes (Medium Rectangle, Rectangle, Leaderboard, Wide Skyscraper) into a set of guidelines it calls the "Universal Ad Package".