Data leakage in online advertising

Data leakage exposes brands, agencies, publishers, and adtech companies to legal hazard under the GDPR and the ePrivacy Regulation.


The video below explains how “programmatic” or “real time bidding” advertising functions.

It this was ever a mystery to you take 43 seconds to watch (and click fullscreen).


Ad exchanges run an auction to determine whose ad will be shown to a user on a website.

The next video, below, shows how data leak from the online advertising system. It shows each step in the selection and delivery of a single ad is serviced on a single webpage. (It takes 33 seconds to watch).



Ad exchanges share their data about website visitors, such as the ad exchange’s own identifier on the user, the URL the user is on, the user’s IP address and details of the user’s browser and system. These data are shared with several hundred prospective advertisers so that they can decide whether to place a bid for that user’s attention.

The online advertising system was not built for data protection. But publishers, brands, and adtech services can prevent data leakage, and protect themselves from risk.