Nike’s “Just do it.” American Express’s “Don’t leave home without it.” Looking around the corporate landscape can make you feel like a killer tagline is crucial to your brand.

I’d like to suggest something that might seem kind of dismissive: The vast majority of the companies in this country not only don’t need a “Just do it” type tagline, it can actually be destructive. (“Just do what”?!)

Here’s why: Nike was founded in 1964. That tagline didn’t drop until 1988, well after the company had established itself. In 1977, for example, their tagline was “There is no finish line.”

But you know what? Nike didn’t die. And you know what else? “Just do it” wasn’t the result of months of toil and agency genius. A producer thought it up the night before a shoot to tie some TV commercials together, and based the line on the last recorded words of a murderer. (Yeah. Kind of creepy, right?)

Let’s take a look at another brand giant, Coke. They’ve had nearly 50 taglines, which, for a company that’s been around for 130 years might seem almost destructively fickle. But Coke serves as an ideal example of what a tagline can and should do, and that is to remain fluid while remaining committed to the brand.

For example, do you know what Coke’s tagline for 1906? “The Great National Temperance Beverage.” (Imagine that tagline over their current obsession with backlit, smiling Millennials sharing cokes in the city.)

It’s a stark example, but it illustrates the point that your target is always moving, that societal norms and transitions demand that your brand keep up, or be left behind.

For most of the companies out there, a tagline should always favor clarity over cleverness. Brands like Nike and Coke have built up an incredible amount of brand equity; we know who they are and what they do. For most companies, that’s not the case. After all, what good is a saucy tag if nobody has the first clue what your business does? And if your target audience changes, or if you find your business in transition, never think of your tagline as set in stone.

What can you do to write a great tagline for your business?

• Keep it simple. Somewhere between “Just do it” and “Don’t leave home without it” is a good goal. Shorter tags tend to be more memorable.
• Keep it unique. Try and include your unique selling proposition. What separates you from your competitors?
• Keep it consistent. If you have a brand voice out there, keep your tag consistent with your brand.
• Keep it clear. If you’re a window company, don’t be afraid to have “windows” in your tag. Remember, Nike already meant “shoes” before they came up with their killer tagline.