We tried integrating shapeshift.io but the price changes rapidly during exchange and although fine for small amounts we found it unusable to add to an ATM (for now) because it would be impossible to guarantee in advance what the rate is, an essential feature for an ATM so instead opted to connect to various exchanges and allow the operator to set their own exchange / wallets and buy & sell %. I totally agree with the 'great idea' BTW, that's why we tried implementing it at the time.