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."