Some ads are now designed to expand into the page when a user rolls over them. This is often a good compromise for when advertisers want more space than is realistically available. This is also becoming a common way of packaging video content within ads. There are a few things to watch out for with expanding ads:
- Require an Obvious, Consistent Closing Mechanism.
The mechanism for collapsing the ads should be obvious, easy to trigger, and in a consistent location for all ads. (If required to include a close button, some advertisers will make it difficult to see and will place it in a non-standard position. Ideally, the ads would collapse on rollout. - Avoid Placing Ad in Mouse Path.
The ad should not be placed in a position where a user has to roll over it in order to click on navigation, content links, browser buttons, scroll bars, or other commonly used page/interface elements. - Avoid Placing Ad Near Interface Elements.
Likewise, the ad should not be placed so close to the above page or interface elements that users accidentally roll over and activate it.