American Express Serve is a prepaid card that allows you make all your payments both online and offline (e.g merchants stores) without having anything doing with your bank account and so there are no bank network charges while making transactions using it's payment services , this even makes it more safe & secured to use at anytime,as long as American Express is an acceptable payment option.
For those who make use of prepaid cards it is also quite acceptable that the prepaid cards are much easy to use. It can be used almost anywhere without having to worry about the exchange fees for international payments. American Express uses a prepaid card and in as much as it also use a prepaid card there's always an 100% guarantee that you could also enjoy the same service other prepaid cards offer to their holders.
Once major downsides of this card is that it is not ecumenical,in the sense that the card is not generally accepted like the Visa and MasterCard which are accepted globally for all types of transaction. Another pull back about American Express is the cost of using the card which is so very expensive for most average individuals / users to afford.