Der Spiegal can sell advertisers ad spots like these, without targeting to specific audiences (but targeting them to specific sections on your site, e.g. differ

Der Spiegal can sell advertisers ad spots like these, without targeting to specific audiences (but targeting them to specific sections on your site, e.g. different ads next to sports news and fashion news), and without tracking who exactly views them, rather relying on general audience statistics (e.g. Nielsen-like surveys of what percentage of German consumers read Der Spiegel online). Perfectly GDPR-compliant, simple, and worked in practice for decades. Of course it's less lucrative than ads based on invasive surveillance, but if those get prohibited, that's a reasonable alternative.