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.