Programmatic

Bid Request — Definition & Explanation

A signal sent from a publisher's ad server or SSP to potential buyers containing information about the available impression — including page URL, user data, device type, ad size, and floor price. DSPs evaluate bid requests to decide whether and how much to bid.

How Bid Request Works

Bid requests follow the OpenRTB specification and contain dozens of data fields. The SSP assembles the request from publisher context, user signals, and inventory attributes, then broadcasts it to connected DSPs within milliseconds.

Why Bid Request Matters for Publishers

The quality and completeness of bid requests directly affects CPMs. Rich bid requests with accurate inventory signals help buyers make confident decisions and submit higher bids.

Frequently Asked Questions

What data goes into a bid request?

Page URL, ad slot dimensions, floor price, device type, operating system, user consent status, geographic data, and contextual signals based on page content.

How does Stellor Media enrich bid requests?

Stellor adds viewability predictions, historical win rate data, and contextual signals to help buyers confidently bid higher on quality inventory.

What is a bid response?

A bid response is the DSP's reply to a bid request, containing the bid price, creative ID, and any relevant targeting information.

Related Terms

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