Question: How do you change an iconic brand to which millions of Americans have an emotional attachment without causing an uproar?

Answer: You don't tell them it changed. (Until you've got proof they still love it.)

In an effort to keep up with the seismic shift in consumer interests, Kraft Heinz recently changed its iconic mac and cheese recipe. In addition to removing all artificial preservatives, the company switched out artificial dyes with a combination of paprika, annatto, and turmeric that maintains the classic yellow hue.

But what the company did next was truly brilliant:

It didn't tell anyone what it did.

OK, that's not entirely true. Kraft actually did announce last April that it planned to remove all synthetic colors and preservatives from its mac and cheese. But the company then simply moved forward, shipping the reformulated version into stores in December. Of course, the ingredients label on the box was updated to reflect the changes, but even many of the most hard-core moms missed that.

Kraft claims it's sold well over 50 million boxes without anyone noticing.

The Big Reveal

But now the silence is over. Having completed what the company calls "the largest blind taste test ever," Kraft has released a major marketing campaign with the theme: "It's changed. But it hasn't." The offensive includes broadcast and online commercials featuring former SportsCenter and late-night TV host Craig Kilborne, along with the hashtag #didntnotice.

So why the cloak and dagger treatment?

Put simply, Kraft was worried that if it made too big a deal about using a different formula, customers would perceive a change in flavor that wasn't really there.

The proof was in the pudding...er, macaroni. According to a story published yesterday in The New York Times, when the company made the announcement last spring that it would be tweaking the ingredients, people began posting on social media their concerns that the mac and cheese would taste different.

The Times continues:

Some on social media even said, shortly after the April announcement, that they thought the mac and cheese tasted different when, in reality, they were still eating the previous version. This is a psychological quirk, well known to food manufacturers, that can stymie well-meaning attempts to make processed foods healthier. "Anytime there's a suggestion of what something should taste like, some aspect of taste, when we try that food, we're looking for it," said David Just, a professor of behavioral economics at Cornell University who is affiliated with the Cornell Food and Brand Lab. "Whenever you have labels like 'healthier' or 'reformulated,' people are looking for the absence of a taste they really like."

Absolutely Brilliant

Although it will be interesting to see how the new campaign affects overall sales, it's obvious that Kraft and its marketing partners got so much right.

Here are a few examples:

They listened to their customers...but were also patient.

"We constantly talk to our consumers and get feedback from them, and we knew they wanted to feel better about the ingredients they serve their families," Greg Guidotti, vice president of meals at Kraft Heinz, told Eater in a recent interview.

"We saw an opportunity in the marketplace to improve our ingredient line, but we didn't want make the change before we had the right recipe."

With initial response overwhelmingly enthusiastic, it appears that the patience paid off.

They maintained transparency without spilling the beans.

Had Kraft kept everything a secret from the beginning, it could have produced a negative effect. But remember, the company did announce changes were coming--almost a year ago.

In doing so, it kept its intentions clear while keeping the secret...and came clean at the perfect time. (Who knew that in marketing "no publicity" could be a good thing?)

They used social proof to work for them, instead of against them.

Wikipedia defines social proof, also known as informational social influence, as "a psychological phenomenon where people assume the actions of others in an attempt to reflect correct behavior for a given situation."

In other words, people tend to follow the crowd. If Kraft chose to announce the release of the new recipe right away, even a few negative comments on social media could have snowballed.

Instead, the company could already point to millions of satisfied customers as proof that the recipe tasted just as good as the original.

Putting It Into Practice

Whether it's customers, employees, or your extended family at the next reunion, the time will come when you're tasked with persuading a group to take your side.

What's the key to convincing?