We're using AdWords API v201809
We need to be able to set bid modifiers for AgeRange, Gender, etc. We're aware we have to use AdgroupCriterionService (not AdGroupBidModifierService) for this and provide the relevant BiddableAdGroupCriterion objects.
It seems, however, to set a bid modifier, we have to use the ADD operator (and not SET). This is because, even though the UI is showing the criteron is enabled (i.e. added), it's added by default and not by user choice. If an adgroup has multiple
AgeRange criterion enabled by default, and you ADD one criterion so you can set its bid modifier, all other AgeRange criterion are excluded/removed imemdiately! This behavior is confirmed in
this post by Srilakshmi on 28/6/2018.
We find this way the API works very strange and confusing. It means we can't set a bid modifier on such criterion before first getting all the existing criterion in an adgroup, ADD them all first so that they are no longer added by default, and then use the SET operator to change the bid modifier.
This doesn't sound right so we're hoping we missed something somewhere. Can you please confirm how bid modifiers should be set for Demographic criterion?
Thanks
Oliver