While global ATM giant Cardtronics struggles to find a sustainable business case for its large fleet of automatic tellers in Australia, another recent market entrant says it is aiming to double the size of its operations over the next three years.Melbourne-based ATM operator Next Payments is rapidly expanding its fleet as it drives profit growth by installing machines at under-banked sites across the country.According to managing director, Tim Wildash, Next Payments will boost the number of machines it manages from 2900 to 6000 by 2021 as banks decommission parts of their networks and merchants agitate for better deals from their ATM operators. "We've found that if you choose your site well by installing them at hotels, gaming centres and retail outlets, people still prefer to use cash," he said."As an independent operator we are careful never to deploy an ATM within eyesight of any bank ATM because consumers will always choose the bank-owned machine."Wildash said that the company's prudently designed network has shielded its revenue base from the impact of the move by major banks to remove fees on ATM withdrawals.Transaction volumes have fallen by only 1.6 per cent since the banks introduced free access to their ATMs.Next is growing profitably, with earnings before interest and tax surging 42 per cent last year to more than $8 million.Users pay an average fee of $2.50 to access a Next ATM, which is shared with the site owner.The fee has not changed since the major banks moved to zero pricing.Macquarie Group holds a 46.5 per cent stake in the business, but a string of new investors has sunk capital into the company this year including former Bank of Queensland chief executive, David Liddy.While Next Payments is expanding its presence to sites where the banks have withdrawn machines, most of the fleet's growth is attributable to merchants switching from other independent ATM operators.This might help to explain recent truncations of the Cardtronics' network, which declined by more than 688 machines in the 12 months to the end of March."We are winning about sixty per cent of our new business from existing independent deployers," Wildash said.Wildash has a deep understanding of the Cardtronics operation through his former role as chief executive of Customers Limited.He effectively planned and developed the Customers Ltd network that now forms the crux of Cardtronics' local business.Next invests heavily in research and development and uses internally-generated innovation to differentiate its offering to merchants.Some ATM providers were hit with chronic maintenance issues when banks began issuing chip-enabled debit cards.Chip-based cards were found to be incompatible with dip reader ATMs.Next Payments developed its own software that allowed chip cards to be read on the old readers.Wildash acknowledges that new digital payment methods such as contactless debit have undermined the primacy of cash, but he is adamant that demand for cash will persist for at least several decades."I don't think it's over yet for cash," he said."At worst, I think cash will have a very long tail-life."Wildash pointed to the unreliability of digital platforms