What is programmatic digital out-of-home (pDOOH), and how is it different from the programmatic ads you already buy online? pDOOH is the automated buying and selling of ads on digital screens in public places, such as billboards, transit screens and mall displays, using the same kind of platforms as online programmatic; the big difference is that one ad play on a public screen is seen by many people at once, so almost everything about targeting, impressions and measurement works differently.
This guide is written for marketers who know online programmatic and want to understand what changes when the "device" is a screen on a station wall. If you are new to digital out-of-home altogether, start with our complete guide to DOOH.
The short definition
In pDOOH, media owners make their digital screens available through supply-side platforms (SSPs), and advertisers buy that inventory through demand-side platforms (DSPs), using rules for which screens, which hours and what price. Software then decides which ad plays on which screen and when. Some buys are auctions and some are agreed deals; our guide to programmatic OOH advantages and deal types explains the options. Terms such as SSP, DSP and CPM are defined in our programmatic DOOH glossary.
Online programmatic vs pDOOH, side by side
| Online programmatic | Programmatic DOOH | |
|---|---|---|
| Where the ad appears | On one person's phone, laptop or TV | On a shared screen in a public place |
| Who sees one ad | Usually one person | Everyone near the screen at that moment |
| What an impression is | One ad load on one device | An estimate of how many people saw one play |
| Main targeting levers | The user's data: interests, history, identifiers | The screen's location, the time of day and the expected audience there |
| Identifiers on the ad | Cookies or device IDs, where allowed | None on the screen itself; any audience data is aggregated |
| Clicks | Possible and often the main metric | Not possible; response is measured indirectly |
| Inventory unit | A slot on a page or in a video stream | A play in a screen's rotating loop |
| Timing | The ad renders instantly after the auction | The ad may play shortly after the bid is won, and is counted when it actually plays |
Each of these rows has practical consequences, covered below.
One play, many viewers: the impression multiplier
Online, one ad served is one impression. On a public screen, one play might be seen by nobody at 3 a.m. and by dozens of people at rush hour. To price and report this, the industry uses an impression multiplier: an estimate of how many people see each play on a given screen at a given time.
Broadsign describes the multiplier in its October 2024 explainer as an index applied to each play on each screen, so that plays multiplied by the multiplier give audience impressions. It lists the usual data sources as media owners' own traffic surveys, anonymised mobile location data, third-party audience research, and cameras or sensors at the screen. Standards are starting to tighten this up. In the UK, Outsmart's February 2026 impression multiplier standard calculates it from Route audience data, separately for each screen, each 15-minute period, each day of the week and each month.
The practical point: a pDOOH impression is a modelled audience figure, not a count of eyeballs. That is fine for planning and buying, as long as you know where the numbers come from and compare like with like.
Illustrative example: turning plays into impressions
Illustrative example. The multipliers and CPM below are assumptions chosen to show the arithmetic, not data for any real screen.
One screen runs a 15-second ad in a 120-second loop, so your ad plays 3,600 ÷ 120 = 30 times an hour. You buy weekday mornings, 7:00 to 10:00, for four weeks (20 weekdays). The media owner's multipliers for that screen are:
| Hour | Plays per hour | Assumed multiplier | Impressions per hour |
|---|---|---|---|
| 7:00 to 8:00 | 30 | 10 | 300 |
| 8:00 to 9:00 | 30 | 25 | 750 |
| 9:00 to 10:00 | 30 | 15 | 450 |
| Per morning | 90 | 1,500 |
- Over 20 weekdays: 90 × 20 = 1,800 plays and 1,500 × 20 = 30,000 impressions.
- At an assumed $12 CPM: 30,000 ÷ 1,000 × $12 = $360.
- Cost per play: $360 ÷ 1,800 = $0.20.
- The 8:00 hour delivers 750 of the 1,500 daily impressions, half the total, from a third of the plays.
Online, 30,000 impressions would mean 30,000 separate ad loads. Here it is 1,800 plays seen by an estimated 30,000 people. Because you pay per impression, a busy hour costs more per play than a quiet one, which is usually what you want. Our DOOH CPM calculator has cost-per-play and loop tools for running your own numbers.
Targeting by place and time, not by person
A street screen does not know who is looking at it, so you cannot target an individual the way you would online. Instead, you choose:
- Screens, by venue type and location, such as stations near offices or malls near your stores.
- Hours and days, when the audience you want is most likely to be there.
- Audience profiles attached to screens, built from aggregated data about who tends to pass at different times.
- Conditions, such as weather or live events, that trigger a particular creative.
The skill is matching a moment to a message. Our guide to dynamic creative based on weather and time shows how conditional creative is set up.
Bidding and delivery are a little different
Programmatic DOOH runs on the same industry standard as online programmatic, extended for screens. AdExchanger reported in December 2022 that the IAB Tech Lab had added DOOH-specific objects to OpenRTB, including a standard place for the impression multiplier, screen location and guidance on the delay between winning a bid and the ad playing, with billing triggered when the creative actually renders.
For a buyer, this means two things. First, there can be a short gap between buying and playing, because screens work through a loop. Second, you should pay for plays that actually happened, so check that your platform reports proof of play. Our step-by-step guide to how programmatic DOOH buying works covers campaign setup in detail.
No clicks, so measurement works differently
Nobody clicks a billboard. pDOOH results are measured indirectly, for example by comparing store visits, sales or searches in areas that saw the campaign with areas that did not, by tracking QR scans and offer codes, or by running surveys of people likely to have passed the screens. Each method has limits, and the location-based ones rely on modelled data. Our guide to measuring pDOOH success explains how to choose between them.
What this means if you come from online programmatic
- Think in moments, not users. Plan by place and time first.
- Ask where the impression numbers come from. Which audience source, how often it is updated, and at what time granularity.
- Compare cost per play as well as CPM. Two screens with the same CPM can deliver very different numbers of plays.
- Design for a glance. Online creative often assumes attention you will not get on a street screen.
- Set up measurement before launch, because there is no click trail to fall back on.
For worked examples of pDOOH budgets in a real market, see our guide to DOOH advertising for retail and restaurants in Singapore.
Further reading from platforms
- Broadsign: What is programmatic DOOH (pDOOH) advertising?
- Moving Walls: Programmatic DOOH explained
- Perion: The fundamentals of OOH: DOOH vs programmatic DOOH