As of May 25, 2018, Google announced that DoubleClick users will be unable to rely on cookies or mobile device IDs to connect impressions, clicks and site activities from DoubleClick logs. Instead, they will be limited to Google’s own Ads Data Hub for those metrics.
For some, this means that they are satisfied to stay within the Google stack. But not every brand’s solution will be and should be limited to Google. If media buyers want to analyze their spend outside of Google’s platform and offer up any attribution, then just using Google won’t work.