[zaguios]

The 3% is there due to the fact that Swift Demand is trying to be more than just another currency. It's also supposed to be able to act as a way to perform normal day to day commerce. This 3% fee is needed to provide buyer and seller protections as well as support the development of new features for Swift Demand. I'm assuming you are asking why you want to use this over Paypal from a vendors point of view and there are several reasons.

The first one being that Paypal isn't known to very trustable and often freezes funds. The second is that I intend to eventually make a very developer friendly API that lets vendors add Swift Demand to their websites very easily. Early merchant adopters will also have the potential to set it up by allowing people to essentially sign up for their service for free by letting people set up a Swift Demand account and automatically transferring Swift Coins to the vendor for a subscription based service (This means merchants can sell their products without ever requiring a user to break out a credit card which could be a potential large source of extra revenue).