Apple shoppers now have three new iPhone models to choose from. The phones come in three sizes and three colors–silver, space gray, and gold.

Apple follows the rule of three in product marketing, presentations and branding. It does so because neuroscience shows that it works.

In his book Insanely Simple, former Apple creative director Ken Segall (who put the “i” in Apple’s popular products) wrote that Steve Jobs was obsessed with simplifying everything, including the “bewildering choices” that greeted Apple’s customers during Jobs’ years in exile. In 1998, when Jobs returned to the company that had fired him twelve years earlier, he dramatically reduced the number of products in Apple’s product line to make it easier on the customer.

Steve Jobs also realized that “mere humans” can only handle so much information. It’s well-known among neuroscientists that people can easily remember up to three ideas or pieces of information. The longer the list, the less likely it is they’ll remember it.

The rule of three is one of the most powerful concepts in writing, speaking, and presentations. It has its roots in ancient Greece when Aristotle said a story should have a beginning, middle and end. In literature, you’ll find three little pigs, three musketeers, and three bears. It’s why the Declaration of Independence guarantees three inalienable rights (Jefferson wrote for the ear). Every successful Hollywood movie follows a three-act structure. And safety warnings are most effective in threes: stop, drop, and roll. People recall information better when the content is presented in groups of three.

The rule of three pervaded Apple’s iPhone and Watch announcement on September 12th. Here are just a few examples.

  • Tim Cook: The Apple Watch is the integration of “breakthrough technology, powerful software, and world-class services.” Cook also said the Apple Watch has become an indispensable part of people’s lives by helping them to: “stay connected, be more active, and live a healthier day.”
  • Jeff Williamson (COO): The Apple Watch Series 4 comes with “Three new heart features.” The new watch comes in three aluminum finishessilver, gold, and space gray. The Apple Watch will come in three models ranging from $279 to $499 for a Series 4 with cellular.
  • Kaianne Drance (iPhone Marketing Director): Kaianne introduced three app developers to show off three capabilities of the new iPhone Xs.
  • Phil Schiller (vice president of worldwide marketing) highlighted three features of the new iPhones (12MP wide-angle camera, improved True Tone flash, and a 12MP telephoto lens). Schiller introduced three new iPhone models in three sizes.

At Apple, the the rule of three in product presentations traces it roots to Steve Jobs who used it frequently. One of Jobs’ most memorable presentation moments was the day he used the rule three to fake out the audience.

In 2007, Jobs introduced the first iPhone. He announced that Apple would reveal “three revolutionary products:” an MP3 player, a phone and an Internet communication devices. After repeating the products several times, he disclosed the big reveal–all three would be wrapped up in one product, the iPhone. It brought down the house.

Steve Jobs also used the rule in speeches. In 2005, Steve Jobs delivered the now famous Stanford commencement address. He began, “Today I want to tell you three stories from my life. That’s it. No big deal. Just three stories.”

You can adopt the rule of three in nearly every business presentation or conversation to simplify the choices for your listeners or to help them follow the content. For example, show your customer three features of a new product or service. Offer your boss three examples for why you deserve a raise. Give an investor three compelling reasons to back your idea. Give your team three instructions.

The rule of three works because it’s simple, catchy, and easy to remember.