The first advantage is that the user does not have to hand over the card to the merchant. The phone remains in the customer’s hand.
The Samsung Pay app uses fingerprint and PIN authentication to pay.
Once the payment is initiated (after authenticating thorough fingerprint or PIN, there is a 30-second window for the the transaction to be completed. The phone has to be brought near the POS machine and the transaction must be initiated within 30 seconds. If it is not initiated within 30 seconds, the transaction will have to be initiated again by selecting the card and using fingerprint or PIN.
Samsung Pay also uses digital tokenisation. What this means is that the card number is not transmitted to the machine. What the phone transmits is a random token number instead of the card number.
Samsung Pay is also secured with Samsung KNOX. Samsung says that with “Samsung KNOX, the phone is constantly monitored for vulnerabilities. Even if the phone is compromised, card information is still safely encrypted within a separate and secure data vault.”