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But I do not find any wrong if ATMS for bitcoin are installed. There may be many shopkeepers who may not be accepting bitcoin or may not be having much knowledge about it. ATMs will deliever fiat currency. So for payment to them fiat currency will be required and ATMS I think are must for this purpose.
Maybe it's easier to start to have a look at currency exchange shops how do they operate, how they handle cach, because they do a really similar activity when they exchange fiat for foreign fiat...
But usually bitcoin is not legally accepted as a currency in most countries, except for some lucky ones...