Disagreed. You can absolutely do all analytics, personalization and marketing in-house on your properties. You only need data sharing if you want to influence advertising on other properties or if you display others' ads on yours.
Whether you want to do so is a different matter. This obviously requires (potentially custom) software and infrastructure, vs throwing in GTM and calling it a day. If there is no regulatory reason for it (there isn't - this aspect of the GDPR is not enforced), most businesses won't bother and will take the easy option.
alt Hacker News
Disagreed. You can absolutely do all analytics, personalization and marketing in-house on your properties. You only need data sharing if you want to influence advertising on other properties or if you display others' ads on yours.
Whether you want to do so is a different matter. This obviously requires (potentially custom) software and infrastructure, vs throwing in GTM and calling it a day. If there is no regulatory reason for it (there isn't - this aspect of the GDPR is not enforced), most businesses won't bother and will take the easy option.