For merchant, it is easy. Only a tablet is required for using the POS- Bitpay, Coinbase etc. Bitpay allows merchants to convert to fiat in a instance, no risk for volatility to affect the earnings. However, it isn't easy to do and there is not a huge adoption rate ATM. The general public are skeptical of Bitcoin and would avoid using it since it is too volatile. Merchants would be more reluctant to accept it after Bitpay started to charge.