Imagine for a moment that, like most websites on the internet, The Markup had ads on our site. (We don’t.)
Which company gets to show you its ad?
When you loaded this page, you triggered a lightning speed auction for your attention.
And yes, this all took place in an instant, mere milliseconds.
We found one ad platform had 650,000 different ways to label you based on sensitive information like visiting places of worship or an interest in addiction.
Read our investigation into Microsoft’s Xandr ad platform and browse through the lists of audience segments.