Real-Time Bidding
Also known as: rtb, programmatic advertising
An automated auction that decides which ad to show you in the milliseconds a page is loading.
Real-Time Bidding is the plumbing behind most display advertising. When a page loads, the publisher broadcasts a 'bid request' containing everything it knows about you — URL, approximate location, device, interests, sometimes an ID — to dozens or hundreds of advertisers. Each returns a bid; the highest wins and its ad renders.
The controversial part is the bid request itself. Because it goes to many parties simultaneously, your data is effectively broadcast to the ad-tech ecosystem on every ad-supported page load, whether or not anyone ends up buying the ad.