What Your Billboard Is Actually Hired To Do

Quick question: Have you ever called a phone number off a billboard?

Yeah, me neither.

Now, I’m sure if this newsletter gets enough reach, someone out there will comment, “I have!” and they will be the smallest represented percentage of something since your uncle found a gold coin that one time at the beach with his metal detector.

Yet I guarantee that you’ll drive by multiple billboards today with phone numbers on them.

A few issues ago, I wrote “What Your Logo Is Actually Hired to Do”, which people seemed to like and find useful. So, let’s tackle another element of marketing and see if we can understand when they work their best and when we saddle them with the wrong assignment.

The Wrong Job Description

I won’t rehash the whole setup to the previous article, but here’s the gist: every marketing element has a specific job to do. And it can usually only do one job well. Yet we try and force other jobs onto them, expecting them to still work.

When someone leaves the company and you get to absorb their responsibilities, does that make you more or less effective at your job? It’s ok; we’ve all been there.

A Billboard’s One Job

A billboard's (or “out of home” if you want to get ad fancy) job is to make sure your name is already sitting in someone's head before they ever need you. It's what marketing scientist Byron Sharp calls “mental availability”.

Picture the actual moment it's supposed to work. Someone's driving to the office or on an errand or to see their mother-in-law for her birthday. They’re half-listening to a podcast, adjusting the sun visor, thinking about anything except advertising. They see your board for three seconds, maybe less.

Nothing happens.

No sale, no click, no form filled out. That's fine, because that was never the assignment.

What actually happened is your name/brand/message got filed away, one more rep in a long game of repetition.

That's what "mental availability" is describing. The goal of top-of-funnel tactics (like billboards) is to build branded retrieval networks in people’s brains, waiting to be pulled forward the moment it's useful.

Which is exactly why the phone number (and URL, if we’re brutally honest with ourselves) is such a strange thing to put up there. A billboard was never built to close a sale, field an objection, or take a call. A sign read at 65 mph structurally cannot deliver on those jobs, no matter how big you print the digits.

What the Science Actually Shows

Let me start with a rule of thumb from the great Luke Sullivan: seven words (or less) and a logo. Maybe an image if it’s simple.

Yup, that’s all you get. It’s frankly one of the reasons why I used to love writing boards when I was a copywriter. It forces you to boil your idea down to its most potent form. If it can work on a billboard, it can work anywhere.

But why so short a limit? Two parts to the same answer: time to read and time to process.

You barely have time to read a billboard while driving by on a surface street, much less a freeway. And with all the other information flying at your brain like music playing, traffic patterns shifting, trying to figure out why your teen is so morose in the passenger seat… your brain can only do so much at once.

Here’s the hard science: a National Highway Traffic Safety Administration driving study found that once a glance away from the road hits two seconds, crash risk starts climbing. And when the Federal Highway Administration went and clocked actual drivers looking at actual digital billboards, the longest glances they recorded came in at under 1.3 seconds.

 1.3 seconds.

Most reading speed studies are done in quiet rooms with pages of text in front of you. Definitely racing down surface streets, trying to make it to work on time or that dentist's appointment you are always running late for.

Marc Brysbaert did one of the most exhaustive analyses on reading speed studies. Over 190 studies inclusive of over 18,000 participants.

He found that the average adult silently reads English non-fiction, in those idyllic conditions, at 238 words per minute. With most people falling somewhere between 175 and 300 wpm.

Converting that to 1.3 seconds:

• At the average (238 wpm): about 5 words

• At the low end (175 wpm): about 4 words

• At the high end (300 wpm): about 6.5 words

If you’ve got an image, multiple logos, and 20 words of copy… not only can nobody read it. But in order to do so, they’d have to seriously increase their risk of a crash. That’s bad marketing mojo on every level.

So, when Sullivan says seven words and a logo, he's not being artsy about his creative craft. He's representing a number the federal government arrived at by watching real people almost crash their cars. Isn’t it nice when art and science line up?

What This Looks Like

The natural question now is: okay, so… how do you make a good billboard? But that’s a whole other article (maybe lol). For now, I’ll point to brands that have done it well just to prove it’s possible

The best example is probably the long-running campaign by The Economist. They leaned into their brand codes: their logo, their typeface, and their brand color. The rest of the boards are one bold statement.

Just follow this link to a Google Images search for “The Economist Billboards” and you’ll see more examples than you need. Some are longer than seven words, but that’s because they’re often not freeway billboards. They’re at bus stops, subway (tube!) stations, etc so the 1.3 second rule doesn’t apply.

But they still exercise incredible discipline, never get wordy, and never ask the board to do a job it isn’t cut out for.

Some other great examples are Chick-fil-A, McDonald’s, and (of course) Nike.

Number’s Up

So… have you ever called a phone number off a billboard?

Now you know why not.

Because that number, hanging up there thirty feet in the air, was a misassigned resource. Just like the second image. Or a busy single image. Or the third copy block (you know you’ve seen billboards like that!).

A billboard has one job to do; don’t saddle it with other jobs. Because when it’s allowed to do its job well, it works great. Helping your brand jump to mind that moment when your target is standing in line somewhere, half-listening to their own thoughts, trying to remember who handles the kind of thing they’re trying to figure out. And their brain, without being asked, just hands them a name.

They probably won't remember the board. They won't remember the highway, or the song that was playing, or the seven words that were there. They’ll just remember the name.

That was the whole job the entire time.

As you drive around this week, take a (safe!) look around and see how many outdoor boards have been given one job vs many. You might be surprised by how many are working multiple jobs just to pay rent.