Marketers said they now struggle to comprehensively measure their targeting across the platforms within their own data management platforms, forcing some to turn to third-party measurement partners and others to be complacent with piecing together the data they do have strictly within Google and Facebook. Say a marketer ran a campaign across Google and Facebook. Now, they can no longer see if an ad reached the same person on Google as well as on Facebook. Google’s changes to its data sharing came ahead of the GDPR enforcement deadline on May 25. The Google DoubleClick IDs once let buyers transfer files of DoubleClick impressions from across Google’s ad products from Google’s DoubleClick Campaign Manager to their own DMPs. At the end of April, Google disallowed ad buyers from using the Google DoubleClick ID to export data. Facebook made a similar move, citing the need to protect people’s privacy. As a result, their view tags are no longer usable by other platforms such as Google’s DoubleClick. Already, some marketers’ say that within their DMPs, they cannot measure views across their Facebook buys, only clicks. Get the full story at Digiday