The Protected Audience API (fka Fledge) provides the capability to exclude users in one or more InterestGroups (IGs) from seeing a non-remarketing ad via Additional Bids (Fledge explainer). When multiple IGs are excluded, the API requires all of these IGs to be joined from the same origin. However, there are legitimate scenarios for advertisers owning multiple domains that are blocked by this requirement.
Legitimate scenarios
Advertisers often times own multiple domains for various reasons, e.g.,
domain per country: foo.com, foo.co.kr, foo.pt, foo.co.uk
domain for different environments: foo.com, app.foo.com
domain for experiments/testing: bar.com, staging.bar.com, dev1.bar.com
For these advertisers, they won't be able to exclude multiple IGs since users have joint these IGs from multiple domains/origins. If we just pick one domain and put in as the joiningOrigin in negativeInterestGroups, only users joint from that specific domain will be excluded. However, the intention for advertisers is to exclude users joint from any of their domain.
Workaround
The Protected Audience API doesn't have the single origin requirement when only one IG is excluded, so a workaround to bypass the single origin requirement for multi-IG exclusion is to creation a single IG which is the union of multiple IGs.
For example, excluding IG1 and IG2 (i.e. NOT (IG1 OR IG2)) is not allowed if users have joint from multiple domains. Advertiser can create IG3 = IG1 OR IG2 and exclude IG3 to achieve equal outcome without the requirement of single origin.
Problem
The Protected Audience API (fka Fledge) provides the capability to exclude users in one or more InterestGroups (IGs) from seeing a non-remarketing ad via Additional Bids (Fledge explainer). When multiple IGs are excluded, the API requires all of these IGs to be joined from the same origin. However, there are legitimate scenarios for advertisers owning multiple domains that are blocked by this requirement.
Legitimate scenarios
Advertisers often times own multiple domains for various reasons, e.g.,
For these advertisers, they won't be able to exclude multiple IGs since users have joint these IGs from multiple domains/origins. If we just pick one domain and put in as the joiningOrigin in negativeInterestGroups, only users joint from that specific domain will be excluded. However, the intention for advertisers is to exclude users joint from any of their domain.
Workaround
The Protected Audience API doesn't have the single origin requirement when only one IG is excluded, so a workaround to bypass the single origin requirement for multi-IG exclusion is to creation a single IG which is the union of multiple IGs.
For example, excluding IG1 and IG2 (i.e. NOT (IG1 OR IG2)) is not allowed if users have joint from multiple domains. Advertiser can create IG3 = IG1 OR IG2 and exclude IG3 to achieve equal outcome without the requirement of single origin.