Targeted online advertising: ecosystem and law

Most free internet services are funded by targeted online advertising, which builds profiles and routes ads to people who meet criteria. The adtech ecosystem has many actors (ad networks, exchanges, DSPs/SSPs, data brokers). Both the GDPR (personal data) and the ePrivacy Directive (cookies) apply. After Wirtschaftsakademie, advertisers may be joint controllers even if they never receive the data. Notice is hard: many adtech firms have no direct relationship with data subjects.

Profiles are compiled from on/offline sources, supplemented by inferred data, and linked to a device via a cookie. Some adtech firms (SMPs, search engines) deal directly with people; others only build relationships with website operators to track visitors. The status of advertisers shifted after Wirtschaftsakademie: even those that never receive personal data may now be joint controllers.

Adtech transparency challenges
Problem	GDPR flexibility / limit
No direct relationship with the data subject	Art 14(5)(b): make info 'publicly available' where direct notice is impossible or a disproportionate effort
Data from many sources / to many recipients	Can notify categories of recipients and general info on sources where various sources used
But identifiable individual sources	WP29: must give the individual source if it is possible (even if burdensome)

Adtech transparency challenges

Problem

GDPR flexibility / limit

No direct relationship with the data subject

Art 14(5)(b): make info 'publicly available' where direct notice is impossible or a disproportionate effort

Data from many sources / to many recipients

Can notify categories of recipients and general info on sources where various sources used

But identifiable individual sources

WP29: must give the individual source if it is possible (even if burdensome)

Key terms - quick answers

What is “Targeted online advertising”?

Building profiles of individuals and routing ads to those meeting set criteria, usually via cookies or similar tech.

What is “Adtech”?

The ecosystem of advertising-technology companies (ad networks, exchanges, DSPs/SSPs, data brokers) that profile and target individuals.

What is “Article 14(5)(b)”?

Exception allowing info to be made 'publicly available' where direct notice is impossible or a disproportionate effort (e.g. indirectly collected data).