How does the auction process work and what are the system metrics' definitions?



The number of valid publisher ad opportunities. Please note: opportunities are environment specific. For example, if a request is made to a tag where the supply source's environment is desktop, only requests from desktop will generate opportunities.  Requests to the same tag from mobile devices will not generate opportunities.


If an opportunity is generated, the StreamRail ad manager starts running in the goal of generating an ad impression. During this process, the ad manager is usually (it may change according to internal optimizations) generating simultaneous requests to all of the ad- sources for the same tier, starting with tier 1. In the example above you can see that 1 opportunity generated 6 requests, meaning there were 6 ad-sources that fit the targeting conditions of this opportunity (Device, GEO, Player Size, WL, BL, etc’) and therefore 6 requests were generated. The request can “become” a Bid or a Pre-Bid error;


A “Request” may resolve to a either a bid or a pre-bid error. Bids are counted when the ad- server of the ad-source replied with a non-empty VAST without errors. Note: certain timeouts are applied during the bidding process so slow-responding servers may fail to generate bids.

Pre-Bid Error 

If the ad-server of the ad-source replied with an empty vast or did not reply on time (approx. 4 secs’)


After getting enough bids, the ad manager chooses the ad-source more likely to generate an ad impression. This ad-sources is loaded and started, which is counted a “win” (this ad- source is the winner of the bidding process). If the winning ad-source ended up yielding an ad impression, the entire flow is complete and the ad manager finishes it’s job. If the winning ad-source resolved to a post-bid error, the ad manager will assign a win to the next- best bidding ad-source. This process repeats itself until the ad manager times out or disposed by the player which loaded it.


The winning ad-source yielded an ad impression (ad video actually started to play).

Post-Bid Error

The winning ad-source could not generate an ad impression. This is mostly related to the demand behind the ad-source, in which case the post-bid error is a VPAID error. However, in some cases this can also be a timeout error (the winning ad-source tried to bring an ad unsuccessfully for too long, approx. 20 secs), a technical integration error (for example, the ad-source is of the wrong VPAID type), or simply because of user churn (e.g. a user closing the page).