Guild Wars 2

Just to be clear you are asking for a virtual gift card for gems. As oppose to the Gem cards that have been in the stores or at places like Amazon for the past year.

http://www.amazon.com/Guild-Wars-2-Gem-Card-PC/dp/B009AYOFI0/ref=sr_1_1?ie=UTF8&qid=1384921417&sr=8-1&keywords=guild+wars+2+gem+card

I don’t know about the vanilla card but I have occasionally gone to my local grocery store and bought a $25 or $50 mastercard gift card and used it and it worked just fine in the gem store.