Indeed Ad Requests and Ad Opportunities on the Source (Channel) and the Campaign (Advertiser) level differ. Let's see how this works on the example of client-to-server logic.
This logic a bit differs if we talk about VPAID and VAST.
VPAID
- Source level (Channel)
When the player that contains our tag is activated, a user's browser sends an ad call to our server. This ad call is also known as ad request. In other words, ad requests metric shows the number of calls sent from user's browser to our ad server. Ad opportunity metric shows the number of times our VPAID unit was loaded into the player. VPAID unit in turn receives the list of campaigns to call over.
- Campaign level ( Advertiser)
Once the list of campaigns is loaded from our ad server we deal with the ad request metric on the Campaign level. Here ad request (ad call) is the number of times our VPAID unit called demand partners from a waterfall. In other words it defines the request sent by our ad server to the server of the demand partners (Adtelligent demand partners or your own partners). Ad opportunity metric on campaign level represents the number of times demand partners responded with their VPAID unit.
To sum up:
Ad request (source level) shows number of ad calls our ad server received from the supply partner (player, ad server etc.).
Ad requests (campaign level) shows how many ad calls our VPAID made to each campaign in the connection.
Ad opportunity ( source level) is the number of times our VPAID unit was loaded into the player.
Ad opportunity (campaign level) is the number of times advertisers responded with their VPAID unit.
VAST
- Source level (Channel)
When the player that contains our tag is activated, a user's browser sends an ad call to our server. This ad call is also known as ad request. In other words, ad requests metric shows the number of calls sent from user's browser to our ad server. Ad opportunity metric shows the number of times we have responded to the player with our wrapper.
- Campaign level ( Advertiser)
Once the wrapper was sent to the player, we deal with the ad request metric on the Campaign level. Ad opportunity metric on campaign level represents the number of times supply partner has called our wrapper and we redirected to the demand partner's VAST.
To sum up:
Ad request (source level) shows number of ad calls our ad server received from the supply partner (player, ad server etc.).
Ad requests (campaign level) shows the number of times we have responded with our wrapper to the player.
Ad opportunity ( source level) is the number of times we have responded with our wrapper to the player.
Ad opportunity (campaign level) is the number of times our wrapper was called and we redirected to the demand's partner VAST.