Digital Out of Home is Now Integrated Into OpenRTB

Out-of-Home (OOH) advertising, also called outdoor advertising, outdoor media, and out-of-home media, is advertising experienced outside of the home. This includes billboards, screens, and posters seen while “on the go”; from the spectacular displays in Times Square to the Kiosk, ATMs and Taxi-toppers below. It also includes place-based media seen in places such as convenience stores, medical centers, salons, and other brick-and-mortar venues.

The medium is ancient, from cave paintings to signposts denoting where the nearest hot meal was to be found. Its recognisable modern form can be traced back to the nineteenth century where brands truly embraced commercial broadcast advertising. 

The most successful forms of OOH media are those which are seen as beneficial to the viewer.

This may be something as ethereal as brightening up the dark skies, to providing shelter from the rain whilst waiting for the bus, to giving a tourist information about where the best shows in town are, or keeping a commuter up to date with the latest news. These benefits always carry an opportunity for a brand message.

OOH Media’s traditional display technology of the past century has been printed paper (and later vinyl) with the 20th century seeing the introduction of electric front lighting and backlighting techniques for night time viewing and simple animation. The late 20th Century also saw mechanical scroller devices enable multiple adverts to be shown in a single frame. 

The 21st century saw digital display technology being introduced at scale in the market, bringing full motion video to the medium. Digital OOH (DOOH) refers to digital screens and displays that show content which is served to them using display instructions and content that has been uploaded to them via network connectivity or a physical data upload. In combination with ‘classic’ OOH the benefits of new technology synergise with the long term presence of the poster to provide efficient and stable reach with dynamic flourish.

Over the past decade the DOOH medium has grown to provide a critical volume of connected screens to the physical world. This has attracted the attention of digital display advertisers who are now integrating the OOH medium into the digital display omnichannel of online, mobile, audio and ctv advertising.

The OpenRTB standard was built prior to large scale programmatic media investment in Out-Of-Home and thus did not consider real-world aspects of Out-Of-Home. As a result, various interpretations and implementations for programmatic Digital Out-Of-Home (DOOH) advertising necessitated a custom implementation between all parties in the supply chain in order to trade together. This lack of standardization introduced significant cost and complexity into the emerging programmatic DOOH channel. 

The unique differences between trading in the online world of digital media and real-world aspects of Outdoor display center around:

  • Multiple/Variable impressions: DOOH is a medium where one advert play (a spot) is viewable by everyone who is in the vicinity of the advert being displayed e.g. One ad  play = multiple viewers/users (this number can be both greater than *or* less than 1 – due to numbers being based on statistical modeling, fractional values (e.g. .32 impressions per ad display) are common. 
  • Highly Variable Physical Size: DOOH adverts can be served on anything from the size of a shelf edge label to the size of multiple football pitches, far exceeding the size range of anything that can be held in the viewer’s hand or viewed on a computer screen. This wide variety of sizes, resolutions and aspect ratios to be accommodated as the physical displays ‘build into’ physical spaces vary, and may contain additional content (e.g. tickers, application, labels) that cause ad slot sizes to vary.
  • Positioning: The size and direction of a DOOH display affects the size of the total possible audience in addition to changing the probability of that audience actually seeing the ad. 
  • Private Networks/Geolocation Information: The majority of commercial DOOH digital displays sit on walled garden private IP networks. This protects the displays from a wide spectrum of internet security issues, but has forced many Media Owners / Publishers to publish proprietary 1st Party playout reports and confirmations and use 1st Party ad servers and/or CMS systems. The use of private IP networks means that DSPs are not able to use their normal IP address geolocation techniques to get information about where ads are delivered, even though publisher-reported locations (e.g. lat/lon, geo information like address, zip, region) are almost always available. 
  • Non-Persistent Connections/Longer Than Real-Time Delays: Most DOOH display panels are at the mercy of congestion on the local cell tower, meaning when there are a lot of people in the vicinity of the ad inventory, the screens serving those ads have a non-persistent internet connection. To mitigate this, some DOOH Media Owners and/or publishers employ ‘forward and store’ technology and give a lead time tolerance from bid request to display. Bids may be requested in advance (to allow pre-buffering or populate “playlists” on devices, and the confirmation of playback may be delayed due to log collection or processing within publisher systems. The current industry accepted lead time from ‘bid confirmation’ to ‘display’ can be up to 2 hours.
  • Proprietary Device Attributes: Unlike the TV, Tablet and Mobile phone market, there are no dominant global brands supplying DOOH screen technology to the market. Media Owners and/or Publishers source their own screen technology from a wide variety of manufacturers, technologies and installation partners resulting in each network having its own proprietary device types,identifiers, and other attributes such as user agent strings.
  • Commercially Critical Ad Quality: One bad advert being served at one time to one person is survivable. One bad advert served at one time to 1000’s of people in a public place will lead to a Media Owner and/or Publisher risking their contract/permission to serve ads to networks of screens. All ads being served on large commercial networks need to be manually pre-approved (typically involving human, visual review) by the publisher (and in some cases other 3rd parties e.g. venue landlords) before any bids can be accepted for display. This means typical lead times for creative approval can be on the order of “working days”. It also means many publishers and networks will prohibit creative rotation, dynamic content, or changes post-approval. 3rd-Party AdServing (3PAS) support (and support for HTML) is possible, but not guaranteed and has limitations around how much control the advertiser has over their creative. 

In November, the IAB Tech Lab released an addition to the OpenRTB 2.x specification to standardize how Digital Out of Home inventory is handled programmatically. The IAB TechLab has collaborated with leading international Trade Organizations, Publishers and AdTech companies in the Out-Of-Home (OOH) media world to formally include OOH in OpenRTB standard for programmatic trading. This collaboration with the OAAA (Out of Home Advertising Association of America) and Outsmart (Out of Home Advertising Association of United Kingdom) has brought together global DSPs, SSPs and Out-Of-Home Media Owners to establish a common implementation of IAB Tech Lab’s OpenRTB methodology. For more information, technical details, and best practices, please refer to the Implementation notes in the OpenRTB 2.x GitHub repository.


About the Author

Tim Harvey
Founder, Knitting Media and Co-Founder, Purl Applications Limited