A reference for advertisers and media buyers

The screen passes the audience

Every guide to out-of-home assumes the screen is bolted to a building. A growing share of it drives through the city instead, and almost nothing about planning, targeting or counting works the same way. This is out-of-home explained from that side.

Start with the guide See the campaign archive

Shopify · New York · Digital screen · 2026

• 21US markets documented
• 12Formats and carriers
• 2020–2026Photographed, not rendered

What moves

Four carriers cover most of it. They differ in who sees them, how long for, and how much of the geography you control.

Start here

• Out-of-home advertising

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

• How impressions are measured

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

• Who does what in this market

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

• What is DOOH?

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

• Formats that move

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

• 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, and where it quietly breaks on inventory that moves.

• Real campaign examples

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

Why the photographs matter

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. Renders show a design. They do not show whether a format works.

Every image on this site is a photograph of a placement that ran, dated and attributed to the brand and the market. Below is a sample; the archive groups more of them by surface and carrier.

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.

There is no pricing anywhere on this site, no vendor rankings, and nothing about earning money by putting ads on your own car. More on how this is edited, and what it leaves out, in about.