Ad impression is a measurement for a number of times ad is appearing on a web page and viewed by visitors. It is determined by the number of times the particular page is loaded. However, ad impressions count may vary as there is no certain way to count them.
Precise your needs
The frequency of generating a new ad is determined by ad refresh rate. Publishers can choose how often they want ads to be refreshed or even not to refresh them at all. The changes can be made in ad unit setting, where the refresh time can be set on 30 seconds, 120 seconds. “No refresh” is set by default, so if you want your ads to be refreshed every n-seconds, you should define it in your ad unit settings.
Don’t forget!
Also, there are few more notes in ADX that publishers should know:
- Ads with yield-maximizing capability, which qualifies for dynamic allocation, can set a refresh rate after Publisher declares it in ADX, otherwise it will be considered as violation of Google ADX policy. “No refresh” option is a default value, therefore, there is no need to declare it for ADX.
- For parent ad units and for the child ad units should be set separate individual refresh rates.
- The refresh feature and its refresh rate are available for all channels where Advertisers can buy your ad placements (demand sources). However, it is worth checking that the refresh rate you set corresponds with the policies outlined for the demand source you are aiming for.
Source : DoubleClick for Publishers
Other articles worth reading:
http://yieldriser.com/what-you-should-know-about-the-most-popular-ad-sizes/
http://yieldriser.com/rich-media-ad-units-choose-the-best/
http://yieldriser.com/what-you-should-know-about-rich-media-ads/
Photo credit: Hernan Piñera via Foter.com / CC BY-SA
