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  • Frank Gussoni

The Math in Media: Out of Home Edition

Updated: Jul 27, 2023

There are many different ways to measure various forms of media. To help my clients achieve the best ROI from their media campaigns, I look to the math behind the media to ensure their marketing objectives and target audiences are reached. With each form of media, there are specific numbers to understand and focus on that truly make a difference. Not only for deciding which mediums to use, but how much to invest in them. While looking at the numbers is important, there are other factors to consider as well.

Out of Home (OOH)

What most media buyers focus on:

Some traditional forms of Out of Home (OOH) media consist of bus shelters, wallscapes, train stations, bus wraps, benches, and taxi tops. But the most popular choice for OOH advertising is through billboards.

When it comes to advertising on billboards, media buyers tend to turn to “the BIG three” in the OOH category. Lamar, Outfront Media and Clear Channel Outdoor currently own the largest share of the “Out of Home” inventory in the United States. It’s for this reason that so many media buyers reach out to them first to fulfill their clients OOH campaign needs.

Media buyers may reach out to one of these sources, or a combination of all three to pull a large list of available OOH opportunities during the time their clients wish to run. They’ll collect information like; availability, location, direction of read (left or right facing), illuminated or not as well as the traffic counts and potential impression levels that each board receives. Once buyers have this information in hand, they will use the numbers to try to determine the best choices.

The impression numbers that media buyers are supplied for billboard advertising comes from Geopath ratings or mobile trip data. This method provides data on the number of people “who likely saw the ad”. Factors like the size of the board, nearness to the road, the size of the road, the sight line of the board as well as the distance from which it can first be viewed. Geopath technology uses cell phone data to also see how fast people are driving which assists in determining how many seconds the board is in the line of sight of a driver.

In addition to determining the number of people, mobile data is used to determine the demographic information as well. Geopath anonymously tracks areas that mobile devices originate from and through Census and Scarborough consumer data, who they believe are passing by a billboard and the interests they may have. Sounds scientific, doesn’t it!

This is how OOH companies show buyers the reach of each billboard, the total impressions an advertiser can expect as well as the value of the board. But if these are the only things that a media buyer considers when selecting the best billboard options for their clients, they are missing many of other key factors they should be considering.

Other Key Factors:

While impression levels are something that my agency looks at when considering a billboard location, it’s very important to do a little more homework to see how accurate the impression numbers really are and how they’ve been calculated.

The numbers can be misleading, especially for digital billboards. Some companies report the total number of impressions that a digital board receives by taking the total number of impressions and dividing them by the total number of advertisers permitted to run in the rotation on the board. But this isn’t always the case. I have personally received impression numbers for back to back billboards on the same roadway, one static and one digital, that were the same. I’ve even seen higher digital numbers even though a brand is only up for several seconds during every minute. How can this be? This tells me that the number of impressions for the digital board were either total impressions or miscalculated and were not divided by the number of advertisers in rotation.

Impression numbers can also be very deceiving with respect to where the actual board is located. In some areas, a roadway can consist of overpasses, on ramps, off ramps, roundabouts, and bends. What the OOH companies don’t tell you is that they include the traffic numbers for all those roads that the billboard may be “within view” of. So, the numbers you get are inflated, even if the board isn’t in direct view of these areas.

Viewability is the key to having an effective billboard campaign. The approach or the distance from which a board can first be viewed, that’s been calculated into the impression numbers, are based on creative that is big, bright, and simple. For each one of my clients, I like to see the true viewability of the creative by testing it to see how far away the creative can actually be seen to determine if a billboard is the right choice for their creative message. The impression numbers don’t matter if a message can’t be read.

With creative comes another list of numbers to consider. Production costs for different types and sizes of boards will vary. One size creative does not fit all. Billboards, Posters and Bulletins all require different creative specs and will incur a variety of charges. The location of a board can also affect the creative specs for a board. I wouldn’t suggest investing in large extensions for boards in states like Florida, as they are not permitted due to weather factors. So, knowing the rules and the fees charged for production should be taken into consideration to understand the effect these costs may have on an OOH budget’s bottom line.

Even after doing all the preparation prior to starting an OOH campaign, it’s important to see what the message looks like by requesting a “proof of posting”. This is a photo of the board with your creative on the date it was posted. These POP’s should always be requested to ensure the proper creative was posted on the right board at the right time. It also gives a real-time view of the area surrounding the board to make certain that it looks as it should. Because OOH companies always share the best photos of a board to close a deal, it’s a good idea to know exactly what the area looks like in the present time. If the view is different because trees have grown or buildings have been put up around it, you may have an issue with the OOH company’s impression numbers.



President & Founder of A3 media.

We’re Type A. We transform media from an expense into a smart investment.

Frank’s Take provides uncommon sense media buying advice for regional and mid-market businesses.

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President & Founder of A3 media. We’re Type A. We transform media from an expense into a smart investment.

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