Glossary · Formats
Expandable
A banner that grows over the page content when the person interacts with it.
In detail
An expandable banner starts at a normal size (for example 728×90) and extends over the page, down or to the side, when the person hovers or clicks. When it is closed or the cursor leaves, it returns to its initial size.
It is a rich media format: it needs support from the site and the platform, and it must have a clear button to close it.
Example
A 728×90 leaderboard that expands to 728×300 on click.