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title: "Introduction to RTB"
canonical: "https://hub.freewheel.tv/space/BC/114098361/Introduction%20to%20RTB"
format: markdown
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Overview Real-time bidding (RTB) is a method of transferring media that allows individual ad impressions to be bid on in real time via an auction. OpenRTB is an open industry standard format for bid requests and responses that allows for efficient and transparent facilitation of ad auctions. How Real-Time Bidding Works Supply Side Platforms (SSPs), also known as inventory sources, generate bid requests when a publisher wishes to fill an impression. Bids on those requests are submitted by Demand Side Platforms (DSPs), and the winning bid is decided by the SSP. The corresponding advertisement for the winning bid is served to the browser or app that triggered the bid request. DSPs can have integrations with multiple inventory sources to allow them to buy media programmatically from a wide variety of publishers. To transact with the inventory source, the DSP needs to understand how to read that given inventory source’s bid request object and also respond in a way that the inventory source can interpret. For this reason, the IAB released a standardized method for structuring bid requests, which allows platforms to integrate more easily. These protocol standards, called OpenRTB, aim to simplify the connection between suppliers of publisher inventory (such as exchanges or SSPs) and the buyers (such as bidders or DSPs). Buyer Cloud generally supports OpenRTB 2.3, but in some cases, fields from OpenRTB 2.5 and 2.6 are supported. OpenRTB Basics The base of the protocol between an exchange and its bidder is HTTP JSON is the suggested format for bid request and bid response data payloads RTB transactions are initiated when an exchange or other supply source sends a bid request to a bidder Attributes are “required” if their omission would technically break the protocol Some optional attributes are denoted “recommended” due to their elevated business importance Bid Requests The top-level bid request object contains a globally unique bid request or auction ID Must have at least one impression object id and imp (impression) are required objects  Bid Requests can also include additional objects that provide more information for the buyer, such as the site or app name Bid Response RTB responses contain bids that reference specific impressions within a bid request An empty HTTP response constitutes a no-bid  A bid response may contain bids from multiple “seats” or from the same “seat”. A seat generally corresponds to a customer of the DSP. Objects in a Bid Response include: BidResponse, SeatBid, Bid Summary of Previous Versions OpenRTB 2.0 provided unified support for display, mobile, and video capabilities OpenRTB 2.1 provided improved VAST video, tablet and location targeting support OpenRTB 2.2 provided improved PMP and non-intentional traffic support OpenRTB 2.3 provided support for native ads OpenRTB 2.4 introduced the digital audio advertising medium to the protocol OpenRTB 2.5 focused on updates in programmatic transactions through improvements in real-time interactions and notices OpenRTB 2.6 provides increased support for CTV ads Glossary of Common RTB Terms This glossary includes terms and abbreviations that are frequently used in conjunction with RTB concepts. Term Definition DSP Demand Side Platform. A system that allows buyers of digital advertising inventory to manage multiple ad exchange and data platform accounts through one interface. HTTP Hypertext Transfer Protocol. The protocol used for communication over a computer network is the most commonly used protocol for the internet. HTTPS is the secure version of HTTP. IAB Interactive Advertising Bureau. The organization that empowers the media and marketing industries to excel in the digital economy.  Impression A term that refers to the point at which an ad is viewed once by a visitor, or displayed once on a web page. JSON JavaScript Object Notation. A minimal, readable format for structuring data. It is used primarily to transmit data between a web server and web client, as an alternative to XML. PMP Private MarketPlace. An invite-only marketplace where high-caliber publishers offer their ad inventory to a selected group of advertisers. Protobuf Protocol Buffers. A method of serializing structured data. It is useful in developing programs to communicate with each other over a wire or for storing data. Protocol A standard set of rules that allows electronic devices to communicate with each other. RTB Real-time bidding. A method of advertising inventory that is bought and sold on a per-impression basis, via programmatic instantaneous auction, similar to financial markets. SSP Supply Side Platform. A system that allows web publishers and digital out-of-home media owners to manage their advertising space inventory, fill it with ads, and receive revenue. This term is largely synonymous with "Exchange". VAST Video Ad Serving Template. A document format that gives video players information about which ad to play, how the ad should display, how long it should play, and whether users can skip it, among other values. XML Short for eXtensible Markup Language. XML is a markup language like HTML. XML is designed to store and transport data.