Invalid Visitor Fallback URL

The visitor fallback URL represents the URL declared in the request or set by an Account Manager to which unsold or invalidated visits should be sent back. Additional tokens can also be added to the fallback URL for more precise data tracking. If the field is empty, the user will be automatically redirected to the brand's website.

We check what campaigns could buy that visit based on their bid, targeting (brand URL, geo, device, etc.), frequency filter, and potential blocking rules. If there is no candidate (too small bids, no one is targeting that visit), then we respond with zero bid and redirect the visitor to the publisher’s fallback.

In the case of domestic feeds, we send to fallback all unsold traffic, and in the case of Zeroclick feeds we send to fallback all invalidated traffic.

If the publisher adds certain tokens to the fallback URL, we can send them some information about why the user was invalidated (e.g. reason for invalidation, domain, etc.).