Whenever your website request for an ad to be displayed on it from an ad server is ad request.
An ad displayed on a webpage is one ad impression. For example, if there are two ads on a webpage, when the whole page loads successfully than that would count as two ad impressions. Consequently, if the publisher having a website, which has 10000 page views per month and has two ads on every page, the publisher could have up to 20000 ad impressions per month. However, the number of ad impressions can vary on ad display as this is just the calculation.
Does the Ad Request/Impression ratio affect CPM or Revenue?
Publisher looks the ratio as impression/request instead of request/impression.
For example, lower the impression/request ratio, lower the number of times an ad is being served on the traffic. On a platform that runs only CPM ads, it directly affects the revenue.
Publisher should calculate it on request for having a better picture of the revenue earned on overall traffic. Platforms can calculate it on Impression, which may not be able to provide the overall revenue picture of the traffic.
If you have any queries regarding ad request or ad impression or if you want to upgrade from AdSense to AdX get in touch with us.