Out-of-home advertising, explained from the moving screen

Most out-of-home guides assume the screen is bolted to a building. A screen that moves through a city is planned, targeted and counted differently: the audience does not pass the screen, the screen passes the audience. This site explains out-of-home and DOOH from that starting point.

Everything here is written for advertisers, media planners and agencies. There is no pricing, no rankings, and nothing about earning money by putting ads on your own car. What there is: the mechanics of a medium where the audience number is modelled rather than logged, and a documented record of what the formats look like when they are actually running.

Start here

• Out-of-home advertising

  The category guide: what the formats are, the three units they are sold in, and what changes once the ad surface stops standing still.

• What is DOOH?

  Digital out-of-home defined, and why treating it as a synonym for digital billboards causes most of the confusion in the vocabulary.

• How impressions are measured

  Circulation, visibility adjustment, opportunity versus likelihood to see — and the four inputs that stop working when the screen travels.

• Formats that move

  Bus, rail, taxi tops, wrapped fleets, mobile billboards. What each one is, and which authority governs it in which city.

• Who does what in this market

  Six roles, how the money flows through them, and a decision tree for which layer to actually call. Not a rankings list.

• Location-based advertising

  Geotargeting, geofencing, proximity and out-of-home compared — including the one that needs nothing from the audience.

• Programmatic DOOH

  How pDOOH buying works without a cookie or a click, what it does better than a direct booking, and where it quietly breaks.

• Real campaign examples

  Eight formats shown as photographs of placements that ran, rather than artwork composited onto a stock billboard.

The evidence behind it

Out-of-home has a proof problem. Almost everything published about formats is illustrated with composites — artwork dropped onto a stock photo of an empty billboard, shot in perfect light with no traffic in the way.

This site is built on the opposite. The campaign archive holds 3,783 photographs of placements that ran, covering 603 brands across 21 US markets between 2020 and 2026, classified by ad surface, carrier and deployment. It is browsable by all three.

Who publishes this

Operated by Firefly. Firefly operates the inventory the archive documents, which is a commercial interest worth knowing about before you weigh anything written here. Editorial responsibility sits with Melih Koray, Marketing, Firefly. Every statistic carries a named source and a date; where the industry has no reliable figure, the page says so instead of estimating one.

More on how this is edited, and what it deliberately leaves out, in about.