Mining pools/farms. So each mining pool/farm funds itself to a % of the profits in the exchange rate at the ATM machine. The owner that buys the ATM machine also sets a percentage. The ATM machine is connected via the internet to the mining pool/farm and the dash is instantx sent to the ATM once someone wants Dash. In fact, we don't even need the ATM, all we need is a customer to go into a store and ask to buy Dash. The store clerk does the transaction, and the customer hands over the cash. This would work with or without a machine. All we need is a map of all the store locations where you can BUY/SELL DASH, the store owner get's a percentage. This can be done with a mobile app, I think.
The best app would be one were you can see a map. On that map lists all the "stores" and "people" around you selling Dash. You can send them a chat and initiate a trade via the app and in person. After the trade you rate them.