You can get better interest rates than you would
get at a bank sometimes, and there are supposedly no hidden fees, although you always have to be careful since these companies are run for a profit, after all.
In other words, your
bank has a cash EURUSD of $ 1.30 but the conversion you
get at the ATM is Visa's rate, hence the Visa fee (but it's typically a nicer spread, or it's
sometimes the international spot rate depending on the circumstances, due to the overhead of electronic transactions).