Glossary
What is Ad request?
Also called: ad call
An ad request is the call a web page or app makes to an ad server or exchange, asking for an ad to fill one ad slot.
हिंदी में पढ़ेंWhen a reader opens a page, the ad tag for each slot sends an ad request. It usually carries the slot size, the page address and signals such as device and location, subject to the reader’s consent choices. With Google Ad Manager, the Google Publisher Tag sends the request with the ad unit path, size, page URL and any key-values.
A request is not the same as an impression. The request is the ask; the impression is an ad that actually came back and served. Some requests return nothing, because no buyer wanted the slot, every bid was under the floor or the bids arrived too late.
Ad requests are the denominator for several key metrics. Fill rate is impressions divided by ad requests, and AdSense coverage is the share of ad requests that returned at least one ad. When requests rise but impressions do not, demand is not keeping up.
Example
A page with 3 ad slots loads 1,000 times, sending 3,000 ad requests. If 2,700 come back with an ad, that is 2,700 impressions and a fill rate of 90% (2,700 ÷ 3,000).
Why it matters to publishers
Every impression, and every bit of ad revenue, starts with an ad request. Tracking requests next to impressions shows where ads are being lost.