What is real-time bidding?
RTB, or real-time bidding, is a method of buying and selling ad impressions through instant auctions that take place as a page or app loads. The highest eligible bid wins, and that advertiser's ad is shown.
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How real-time bidding works
When someone opens a page with ad space, the publisher sends information about the impression and the user to an ad exchange. Advertisers' platforms receive it, decide whether it fits their targeting, and submit bids.
The exchange picks the winner and the ad loads, all within a fraction of a second.
RTB and programmatic advertising
RTB is one way to buy programmatically. Programmatic also includes private deals agreed in advance but delivered through the same software, which can offer more control over where ads run.
What advertisers should watch
Because buying happens at speed and scale, set clear targeting, budgets, and brand safety rules. Review placement reports and viewability so you know where your money went.
Common questions
Is real-time bidding the same as programmatic advertising?
No. RTB is a type of programmatic buying that uses auctions. Programmatic is the wider category of automated ad buying.
Who takes part in RTB?
Publishers sell through supply-side platforms, advertisers buy through demand-side platforms, and ad exchanges run the auction between them.
How fast does real-time bidding happen?
In a fraction of a second, within the time it takes a page to load.
Does RTB use personal data?
Bid requests can include information about the user and context, and rules on data and consent apply. Privacy laws and platform policies shape what is shared.
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