There is a reason every concert and sports venue near me has gone cashless. It's not because they enjoy giving away 2-3% of their revenues but rather those places aren't active every evening and tend to turn over employees quickly. Handling cash is expensive and risky in that environment.
In a concert and sports venue concessions environment you're also prioritizing throughput much more than most businesses. Being cashless helps with throughput a lot - the employees don't have to wait for people to count their money, then recount it, and spend time making change.
