They cannot tie back impressions as they only deliver those on their platforms, they dont’t have an exchange like Google. If you are talking about third party i

They cannot tie back impressions as they only deliver those on their platforms, they dont’t have an exchange like Google. If you are talking about third party identifier online syncs, any decent ad blocker will stop those. Offline syncs break after time. Data policies don’t allow you to keep anything older than 13 months.