Bid Request and Response

  • Bid Request: In programmatic advertising, a bid request is a data packet sent from a publisher’s ad server to an ad exchange, indicating that there is an ad slot available. This request includes details about the ad slot, the user, and the context in which the ad will be displayed.
  • Bid Response: A bid response is what advertisers or their demand-side platforms (DSPs) send in reply to a bid request. It includes the bid price (how much the advertiser is willing to pay for the ad slot) and the ad creative to be displayed if the bid is successful.

Simplest Definition: A bid request and response are the core components of programmatic ad buying, where a publisher requests bids for an ad slot and advertisers respond with their offers.

Why is it Important?

  • For Publishers: It allows them to sell their ad inventory in real-time to the highest bidder, maximizing revenue.
  • For Advertisers: It offers the opportunity to bid on ad spaces that are most relevant to their target audience, optimizing their ad spend.

How Does it Work?

  • Initiation of Bid Request: When a user visits a website, the publisher’s ad server sends out a bid request to various DSPs.
  • Details in Bid Request: This request includes information like user demographics, browsing behavior, the content of the webpage, ad slot size, etc.
  • Bid Response from Advertisers: Advertisers, through their DSPs, evaluate the bid request and respond with a bid price and the ad they wish to display.
  • Ad Selection: The highest bid or the most relevant ad wins, and that ad is then served to the user.

Historical Context

Bid requests and responses became prominent with the rise of programmatic advertising and real-time bidding (RTB) in the early 2010s, revolutionizing how online ad inventory is bought and sold.

Practical Applications

  • Real-Time Ad Buying: Advertisers can make instant decisions on which ad slots to bid on, based on real-time data.
  • Dynamic Pricing: Publishers can get the best possible price for each ad slot through an auction-based approach.

Benefits and Drawbacks


  • Efficient and automated buying and selling process.
  • Targeted advertising leading to better ROI for advertisers and higher revenues for publishers.


  • Complexity of the programmatic ecosystem can be daunting.
  • Potential privacy concerns with user data being shared in bid requests.

Industry Examples

Major online advertising platforms, such as Google’s DoubleClick, utilize bid requests and responses in their programmatic advertising operations.

Related Tools and Technologies

Programmatic advertising platforms, Demand-Side Platforms (DSPs), Supply-Side Platforms (SSPs), and Ad Exchanges are key tools and technologies involved in this process.

Future Trends

The future may see increased transparency and privacy-focused changes in how bid requests and responses are handled, especially given global data privacy regulations.

Best Practices

  • For Publishers: Optimizing ad inventory to make it attractive in bid requests.
  • For Advertisers: Using data effectively to make informed bid responses.

Legal and Ethical Considerations

Compliance with data privacy laws and ensuring ethical use of consumer data in the bid request and response process is critical.

Common Misconceptions

  • Myth: Bid requests and responses are only about the highest bid.
  • Truth: Relevance and ad quality also play significant roles in the selection process.

Expert Opinions

Experts highlight the importance of leveraging technology to enhance the efficiency and effectiveness of the bid request and response process in programmatic advertising.


Q: Is the highest bid always selected in a bid response?

A: Not necessarily. Ad relevance and quality also factor into the selection process.

Q: Can small businesses participate in bid requests and responses?

A: Yes, businesses of all sizes can engage in this process through programmatic advertising platforms.