Mobile wallets, cardless transactions and person-to-person payment technology get a lot of attention, but at the end of the day, some people – and especially millennials – would rather just use cash, according to a new study by ATM servicer Cardtronics.

Investors have plowed billions into technologies and companies striving to disrupt the world of payments, but Cardtronics found cash use actually increased over the past year for 37% of the 1,015 adults surveyed between Nov. 10 and 12, 2015.

"Cash is king for many consumers, even in today's expanding universe of digital payment options," Cardtronics Chief Marketing Officer Tom Pierce said. "Our survey data clearly shows that in a competitive payments environment, cash is a predominant payment form and sits atop multiple spending categories."