The craving hit hard. My husband and I were driving back to town late one Saturday night after a U2 concert when we were both suddenly struck with the urgent desire for some Jack in the Box tacos. At once we began scanning the roadside signs, hoping to spot our desired destination.  

As we sped by signs for all of the fast food restaurants, another thought hit me as well: A good logo makes a big difference.

Of course, this was not a new idea to me, since I’ve been working with brands for more than 20 years. But noticing how differently the signs lit up in the black night sky really drove the point home. Some were easy to read; others weren’t. Some really popped; others didn’t. Some looked fun and clever; others looked boring.

In that moment, I also remembered that how the logo looks at night atop a 50-foot pole on the side of a highway is only one factor a quick serve must consider when developing one. There are many other considerations that go into a making a logo into a strong cultural icon—and I thought I’d break them down here.

But perhaps I should explain why a good logo is so important in the first place. Ultimately, we humans are a visual species. We use visual signals to understand and navigate our world. As consumers, we use visual brand signals like logos to understand and navigate our purchase decisions.

A logo helps us identify what we’re buying. It enhances our brand recognition and recall, and gives us a sense of the brand character and personality. It also helps us differentiate between offerings.

Companies use logos to reinforce their brand identity (Blockbuster’s logo is a movie ticket) or to highlight a brand attribute (Prudential’s rock logo evokes dependability). Sometimes logos are used to symbolize a desired repositioning—BP introduced its flower-like logo in an attempt to position the company as environmentally friendly.

Logos are powerful communicators. And among all of the brand communication out there these days and the shrinking size of the screens through which brands are communicated, a good logo is critical to capturing people’s attention and increasing a brand’s visibility.

But impact is only one dimension of a logo’s power. A logo must also achieve contact. The former is about visibility, stating what the brand is and stands for; the latter connects the brand to the customer, making a personal, emotional connection. So a good logo design balances catching people’s eyes and appealing to their emotions.

Versatility is another quality of a strong logo. It’s important to look at all the ways the logo will be used before selecting one, like on packaging, newspaper advertising, TV commercials, retail environment, promotional materials, vehicles, uniforms, mobile phone apps, and so on. Some companies use a flexible logo to address these issues. Gucci uses its full logo in some applications, and only the G in others.

The colors of a logo impact its effectiveness. Brighter, bolder colors make the brand easier to spot, but they can sometimes cheapen the brand image. Using multiple colors increases the visual interest of the logo, but it also increases production costs.  

Certain colors have become industry conventions. Green usually signals healthy or fresh products; most technology companies gravitate toward blue. It seems like red, orange, and yellow are quick-serve favorites, so a fast food brand that’s trying to differentiate itself from existing options might want to choose different colors. But a quick serve that wants to make its offering seem more conventional, say a new ethnic concept or a higher-end chain moving into the quick-serve sector, may use the category colors to its advantage.

There’s a lot of debate about which is more powerful, a logotype (a designed treatment of the brand name, like Microsoft’s logo), a symbol (a graphic, like Apple’s), or a combination of the two. People also argue whether an abstract symbol (Nike’s swoosh) or a literal one (Lowe’s house) is better.

I don’t think there’s a hard and fast rule, other than simpler is better. The more complex the logo, the longer it takes people to recognize, understand, and recall the brand.

Consistent use will make or break a logo. For consumers, consistency breeds familiarity, which in turn increases liking and trust. For companies, using logos consistently protects them from trademark infringement by copycats.

Other usage principles can be summarized in a quick list of do’s and don’ts. First, do maintain the highest quality standards for your logo—blurry lines and colors that are slightly off reflect a lack of attention to detail and professionalism that turns off customers. Also, do refresh your logo from time to time to keep it relevant and interesting. And do publish a standards manual to outline the proper usage of the logo.

But don’t overuse the logo—crassly slapping your logo on every surface can fatigue customers—and don’t be too trendy—the core of your logo design should be timeless.

Above all, the most important point is that a logo is only as effective as the meaning that’s associated with it. Everyone wants a logo like McDonald’s; after all, some children recognize and respond to those golden arches before they can even walk. But McDonald’s logo is powerful only because it’s spent billions of dollars promoting it and has consistently applied it to everything it’s done for nearly 50 years. It now conveys all the meaning and associations of the McDonald’s brand. It’s a cultural icon.