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Real-Time Bidding

An auction-based system where ad impressions are bought and sold in milliseconds as a webpage or app loads.

Reference definitionGoogle

What Real-Time Bidding means

Real-time bidding (RTB) is a programmatic auction mechanism where individual ad impressions are bought and sold in the time it takes a webpage to load (typically under 100 milliseconds). When a user visits a page, the publisher's ad server sends a bid request containing available user data (device, location, context, and possibly behavioral data) to multiple demand-side platforms, which evaluate and bid in real time. RTB has faced significant privacy scrutiny — the IAB Europe's implementation of RTB was found to violate GDPR by the Belgian DPA because bid requests containing personal data are broadcast to hundreds of potential buyers, creating a data sharing and security concern. This ruling has implications for the entire programmatic advertising ecosystem and is driving the industry toward privacy-preserving alternatives like Google's Privacy Sandbox Protected Audience API.

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