Definition:

A banner is a graphical advertisement integrated into a web page, application or another digital environment. It may combine images, text, animation, video and interactive elements, and it normally directs the user to an advertiser’s page when clicked or tapped.

Its objective may be to build awareness, communicate an offer or attract visits and conversions. Banners can be purchased directly from a publisher, distributed through advertising platforms or included in monetisation systems such as Google AdSense.

What banners are used for

Banners display advertising messages in spaces associated with an audience, content or context. They are used to promote brands, products, services, events and content, as well as to reach audiences that have already interacted with a website or application.

The creative can be adapted to the publisher, device and campaign stage. An awareness banner may prioritise visual recognition, while one intended for direct response may emphasise an offer and a particular action. Placement, frequency, relevance and advertising saturation all affect the outcome, so the presence of the banner does not guarantee attention.

How banners are measured

Metrics depend on the campaign objective. Common measures include impressions, viewable impressions, reach, frequency, clicks, CTR, cost and conversions. CTR is calculated by dividing clicks by impressions and multiplying the result by one hundred.

A high CTR does not by itself demonstrate that a banner generated value. Evaluation should also consider traffic quality, subsequent actions, cost, attribution and, for brand campaigns, measures of coverage or recall. Accidental clicks and invalid activity can also distort the interpretation.

Types of banners

Banners can be classified by the way they present the message and respond to the available space:

Static: These use a fixed image and a message that does not change during the impression.
Animated: These display a sequence of elements, normally through GIF or HTML5, to develop the message in several stages.
Rich media: These include video, audio, expansion or other interactions that require implementation compatible with the publisher.
Responsive: These combine assets and dimensions so they can adjust automatically to different advertising spaces and devices.

Banner formats

Different sizes and placements are used in display advertising campaigns. Recognisable historical and current formats include:

Horizontal banner or leaderboard: This is commonly placed in headers or between content blocks; 728 x 90 pixels is a frequent dimension.
Skyscraper: This occupies a vertical column, with dimensions such as 160 x 600 pixels.
MPU or medium rectangle: This is integrated into the content body or a column; 300 x 250 pixels is a common size.
Expandable: This increases its area after a defined interaction without permanently occupying the full expanded space.
Interstitial: This appears between two screens or stages of navigation and occupies much of the visible area.
Floating or overlay: This appears above the content and may remain fixed until it is closed or its exposure time ends.

Overlay formats can interrupt navigation and encourage the use of an ad blocker. They should therefore provide appropriate closing controls and comply with accessibility, performance, platform and publisher requirements.