To add to @grzegorzewald’s answer:
It’s correct that you’d expect that behaviour, I would make one picky correction that the
network_userid is only a third party cookie where you’re setting it on a third party domain. It’s a first party cookie when you’re setting it on a first party domain - in other words if you own the domain you’re tracking in, Snowplow is a first party data collection tool and this ID can be configured as such.
@volderette some advice in your tracking setup - I recommend against using the
domain_userid fields for this. Doing that leaves you open to a data modeling logic nightmare whereby a column in your database represents two separate things - this goes against how we design Snowplow.
If you use our android and iOS trackers, you can enable the mobile context to automatically send IDFA & adID values. If that doesn’t meet your requirements I strongly recommend using a custom context to track this data - otherwise you’re creating a lot of work downstream in parsing out the defnition of a value on a per-row basis, and once you start to track on the web as well, this problem will become all the more painful.
Hope that’s helpful!