This breaking news comes from an SOE GM (we are withholding the name):

As part of having an actual subscription through us is the fact that you get to use the bonus items unlike if you use a prepaid card. They get the special perks because they use us direct rather than going through a third type payment option. So yes, there is a benefit to have an account through us rather than a pre paid monthly gaming card. It may not seem fair that a player may have been playing for years with prepaid cards and feels they deserve the items, but the fact is that players who come to us direct made a commitment and thus reap better rewards.

Another thing with having a subscription is that we do give discounts when you purchase a 3 month or even a 1 year when you use a credit card. I hope that this information is helpful. If you have any further questions please let us know and we will be happy to help.

From the EQ2 Forums.