Burger King is asking its restaurants to put good vibes ahead of order speed.

This means, for example, offering a cardboard crown to each customer — no exceptions.

“Say it’s a guy who’s like 38 years old, no kids in the car, and I got to say to him: ‘Do you want a crown?’ You can’t help but smile when you say that, and he can’t help but laugh back,” said Deborah Derby, the chief executive officer of Burger King’s largest U.S. franchisee, Carrols Restaurant Group Inc. “It forces that extra two minutes of engagement.”

The burger chain is giving a higher weight to patrons’ complaints than to speed of service when measuring guest satisfaction.

Since expansion opportunities are now going to only the highest-scored franchisees, operators are paying close attention to diner feedback, while still seeking to get food out as quickly as possible. It’s part of a $400 million plan to boost store traffic and reverse years of slumping sales. Burger King is also sprucing up restaurants and boosting advertising.

Research at Burger King, owned by Restaurant Brands International Inc., has shown that customers can perceive friendly staff to be faster than they actually were. One way to make interactions with diners more memorable — and potentially curb complaints — is Burger King’s requirement that workers offer guests the signature cardboard crown, Derby said. Staff is required to say “you rule,” a new spin on the company’s decades-old tagline.

While corny, the exchange creates a “positive aura” that earns restaurants credit with diners, according to Derby. Her company, which operates more than 1,000 Burger Kings in 23 states, seeks to get food into customers’ hands about a minute and 25 seconds after they order. But positive interactions earn workers a few extra seconds if the rest of the order is otherwise correct.

Burger King conducts store visits to monitor whether workers are saying “you rule” and offering a crown, Derby said. The chain also verifies that Whoppers are coming out at the right temperature, among many other checks.

The customer-satisfaction element is part of Burger King’s assessment of its franchisees, and a good score will have tangible financial benefits for restaurant owners. Last year, Burger King said that only the best operators will be allowed to expand. Top franchisees on average generate profits 65% higher than the rest of the system, executives have said.

The company declined to offer more details on the specifics of how it measures franchisee performance beyond food that’s hot, served quickly and “with great service.”

Burger King executives have previously said the chain is getting fewer complaints from diners. The chain recorded flat customer traffic in the third quarter of last year, an improvement after declines in previous periods. Carrols has posted higher traffic in the last two quarters.