While visiting Pennsylvania Amish country in the 1970s, Alan Siegel, founder and chairman emeritus of global brand strategy, design and experience agency Siegel+Gale, saw a sign that struck a chord. It read: simple is smart.

Decades later, the notion still rings true for him. “We continue to operate with a tagline that Alan landed on in the 70s,” says Howard Belk, co-CEO and chief creative officer. “We’re still known as the simplicity company.”

Just why is simplicity so important? “We live in a very complex and sometimes a confusing world,” says Belk. “Throw into the mix that there are some bad actors out there, using complexity to take advantage of people and confuse consumers.”

To prove the idea that there’s a link between simplicity, consumer trust, and business success, Siegel+Gale has conducted an annual report called the Global Brand Simplicity Index for six years running. It ranks several hundred of the most recognized brands, from ALDO to Zara, according to how simple 12,000 consumers from all over the world perceive them to be, through online surveys.

Though the rankings change yearly, one thing remains constant. “If consumers view a brand as complicated, they feel it’s being complicated on purpose, or trying to take advantage of them. They won’t trust them as much,” says Belk. “That’s why consumers now are demanding simpler and clearer experiences and relationships, because they feel more honest.”

And if you want to see simplicity really in action, just pay a visit to Siegel+Gale’s headquarters in the Chelsea neighborhood of New York City, where one of the company’s nine practices is wholly devoted to, yes, simplification. It’s a group “made up of information designers, rhetoricians, and language specialists that look at complex systems of information and simplify them,” says Belk.

“Everyone’s really integrated,” says Anne Swan, the executive creative director. “We’re a creative agency, but we’re constantly thinking about how businesses work and how to solve business challenges. That’s why we work so closely together.”

As for the kind of people drawn to Siegel+Gale, Swan says, “They’re smart, nice (in an elegant way, not sugary), and unstoppable.” They also happen to be an incredibly diverse bunch. In a meeting “you could be with a PhD who wears a pocket protector and a former drummer in a rock band,” says Belk. “But they all like working at a firm that’s a leader, and… with brands that millions of people touch every day.”

For example, in March 2014 Siegel+Gale client CVS announced it would be the first pharmacy to take tobacco off its shelves for good. The move could potentially cost them $2 billion in annual revenue, but instead, they viewed it as a prime time to restate who they were and what they were ultimately about: good health.

After a thorough review of the business and how consumers used CVS, Siegel+Gale created a cohesive message by uniting their four service brands CVS/pharmacy, CVS/specialty, CVS/minute clinic and CVS/caremark. What resulted was a new name–CVS Health—a new logo and identity system (a hard-angled heart), and new tagline: “helping people on their path to better health.” Swan says, “They all fit together now. We created a new story for them, to help connect all of their businesses. Now, the entire experience is easier to navigate.”

Simpler, too, of course.