Besides, as other commenters have pointed out, there is no concrete evidence that targeting individual users is any better (in terms of bringing in more sales) than targeting the combination of region, language, website topic, and on-page keywords.
If you're so worried about the sustainability of European ad agencies, maybe you should stop fearmongering and start trying to improve contextual targeting technology to such an extent that it provides even more value to your customers than behaviorally targeted alternatives. If and when GDPR-like regulations arrive in other parts of the world -- I'm pretty sure the noose is getting tighter in the U.S. as well -- your European agency will be in a perfect position to grab market share there.
