Cashless gaming has been used on slot machines throughout the casino industry for at least two decades, although it wasn’t initially accepted by customers.

When the original systems, dubbed ticket-in/ticket-out, were introduced, they confused older slot players, who didn’t understand why winnings came out in the form of a ticket voucher, rather than cash, which they had originally loaded into the machine.

Everi Holdings CEO Mike Rumbolz remembers those days vividly. He was vice chairman of Casino Data Systems when the company deployed one of the earliest ticket-in/ticket-out devices. Twenty years later, Rumbolz is leading Las Vegas-based Everi’s efforts to develop products in the cashless gaming space, one of dozens of gaming equipment providers and technology companies seeking a foothold in the now-expanding segment.