Patrons of Sweetgreen are very particular about their salads. When the company recently removed bacon and sriracha from the menu, customers took to social media to complain. But after a handful of Sweetgreen restaurants stopped accepting cash in January, barely anyone noticed, according to the company's owners.

Even Sweetgreen executives thought going cashless was "a harebrained idea" at first, said Jonathan Neman, a co-founder and co-chief executive of the company. "But we looked around and saw that airlines haven't been taking cash for a while." At Sweetgreen's locations throughout the United States, cash purchases have declined to less than 10 percent today from 40 percent of all transactions when they opened their first location nine years ago, he said. Sweetgreen now has 48 locations.

Although America is far from becoming a cashless society, cash transactions are less frequent than even a few years ago and some restaurant owners are betting that customers will be comfortable doing away with cash for convenience.

Restaurants like Sweetgreen are pushing credit and debit cards and mobile apps for payments. Apps enable restaurants to gather data and feedback, and allow consumers to order ahead and skip long lines.

"One of the biggest complaints at Sweetgreen is the line, so by reducing cash we're able to serve customers a lot faster," Mr. Neman said. At the six Sweetgreen locations where cash is not accepted, employees can perform 5 to 15 percent more transactions an hour, he said.

In a cash-free environment, employees are also safer, Mr. Neman said. There have been only a handful of thefts and robberies since Sweetgreen has been in business, but he said he believed that going cashless deterred thieves. "I don't think anyone's coming in to steal arugula."

"I think they were ahead of the trend," Sam Oches, editor of the quick-service restaurant industry magazine QSR, said of Split Bread. Sweetgreen might have an easier time this year, because of increasing app use and the brand's popularity. "Sweetgreen is very emblematic of the future of the fast-casual industry," Mr. Oches said. "If anyone is going to make this work, it'd be them."

Going cash-free, though, can seem to run counter to restaurant hospitality training. The hardest group to persuade of the benefits of a cashless environment might have been his employees, said Alan Bekerman, the founder and chief executive of iQ Food, a chain of healthy fast-casual restaurants in Toronto. When Mr. Bekerman started discussing his cashless plan with employees, they were aghast.

"We are bred to say 'yes' to everything," said Mr. Bekerman, who opened two cash-free restaurants in February and plans to convert his three other locations by the end of the year. "But when we jumped in and did it, there really hasn't been nearly as much chaos or hate mail or pushback or that stuff that we're used to getting when we make changes as we expected."

To read the complete article, see:
At Sweetgreen, a Suitcase Full of Cash Won't Buy You Lunch(www.nytimes.com/2016/07/31/business/where-a-suitcase-full-of-cash-wont-buy-you-lunch.html?_r=0)