There are two ways to answer the question of how to write an advertising slogan.

The first approach is to talk about the general rules that guide all (or most, but we’ll get to that) of the greatest slogans out there.

There have been various attempts to categorise them, but the essentials can be boiled down to something like:

1. Keep it short; usually 6 words or less (Kellogg’s Frosties – “They’re gr-r-reat!)
2. Make it memorable (Nike – “Just do it”)
3. Convey your unique selling point (HSBC – “The world’s local bank”)

This approach shows you the parameters for your slogan. It’s important to familiarise yourself with these rules and recognise that they have shaped all slogans out there.

This theoretical approach is important, but to quote the famous German poet Goethe, “all theory, dear friend, is grey, but the golden tree of life springs ever green.”

Goethe clearly wasn’t a slogan writer, so let’s condense his helpful insight into one:

“Theory is grey. Life is green.”

This slogan is short (at the 6 word limit), punchy and uses an economy of words. These are essential components that are particularly important when it comes to the question of how to write a billboard slogan.

How to write an effective billboard slogan

Keep it short

Just like a poet, you need to make every word count.

Economy is key. A typical slogan uses no more than 6 words. Here are some of the best slogans out there:

• Kit Kat – “Have a break, have a Kit Kat” (6 words)
• Red Bull – “It gives you wiiiings” (4 words)
• McDonald’s – “I’m lovin’ it” (3 words)

Make it memorable

There is only one reason why you would go over the 6-word limit: if your idea is absolutely brilliant (all rules can be broken if done brilliantly). Here are some famous slogans that are 7 or more words long and have embedded themselves in our collective memory:

• Carlsberg – “Probably the best beer in the world” (7 words)
• Maybelline – “Maybe she’s born with it, maybe it’s Maybelline” (8 words)
• Ronseal – “It does exactly what it says on the tin” (a whopping 9 words but it’s probably one of the best slogans in the world, to paraphrase Carlsberg)

Convey your unique selling point (USP)

A slogan can take the most distinctive facet of your product and distil it into a catchy epithet.

Subway have taken this approach. They’ve looked at the downside of fast food, it’s unhealthy, and used a very straightforward slogan that positions them as a healthy fast food option; “Eat fresh”.

Not all slogans have to overtly convey value, however. McDonald’s slogan “I’m lovin’ it” makes no claims about what the brand offers, other than the assurance that you’ll “love it”. They could have plugged a facet of their USP, but would “fast food you’ll love” have had the same affect? With slogans it’s the way you say it as much as what you say that counts.

Going deeper into writing a killer billboard slogan…

It’s worth putting in the time to really study popular slogans and find out what makes them tick. Here are some less talked about ways to craft a winning slogan.

Be humble

This may sound counter-intuitive. It’s tempting to design a slogan that makes your brand look like some kind of world-changing movement for personal and/or social betterment. Some brands do manage to do this, like Adidas’ “impossible is nothing” slogan from 2004. But most shy away from it.

Use irony

Carlsberg deliberately send up the hyperbolic nature of some advertising with their slogan “probably the best beer in the world”. If their slogan had been “the best beer in the world” that would have made them look arrogant (and no doubt got them in trouble with Advertising Standards) and that would have turned off consumers. By adding “probably” they add a touch of irony to their slogan, tacitly acknowledging that such claims are rather silly. This makes them look endearing rather than arrogant.

Embrace the humble brag

One of the best “humble brag” slogans in recent years (and ever) is from MasterCard:

“For everything else, there’s MasterCard.”

The genius of this slogan is its acknowledgement that there is more to life than materialism; that you can put a price on material things, but the experiences that make life worth living are “priceless”.

MasterCard do not pretend that they can make you whole, or that by using them you will have some kind of life-enhancing experience. By doing this, by limiting the scope of what their brand can do for you, they actually end up bigging themselves up.

They’re saying that they are the go-to credit card company without literally saying that. If their slogan had been “the best credit card in the world” they would have looked arrogant (and dull). If it had been “the credit card that makes life worth living” they would have looked arrogant and ridiculous. They would have overstepped their territory in terms of what value they can get away with saying they provide.

All this goes to say that creating a successful advertising slogan is as much an art as a science. And remember, life is green.