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Advertising Platforms & Infrastructure
3 min read
Real-time bidding, or RTB, is the auction mechanism at the heart of programmatic advertising, where each individual impression is auctioned and sold in the milliseconds it takes a page to load. It is what makes impression-by-impression buying possible at web scale.
An impression appears. A page load triggers a bid request.
Buyers evaluate it. DSPs assess the user and context instantly.
Bids are submitted. Each buyer offers a price in real time.
The winner serves. The top bid’s ad loads with the page.
Bid request. Details of the impression are broadcast.
Valuation. Each buyer estimates the impression’s worth.
Auction. Bids compete for the slot.
Delivery. The winning ad is served.
Granularity. Every impression is priced on its own.
Efficiency. Buyers pay only for impressions they value.
Scale. Billions of auctions run continuously.
Data reliance. Good bidding needs good signals.
Latency limits. Everything must resolve in milliseconds.
Fraud. Fake impressions can enter the auction.
Privacy shifts. Less user data changes how bids are valued.
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