At first, this struck us as bizarre, but it actually makes some sense. A 7-Eleven representative is quoted in the Worlds in Motion article saying that the cards are perfect for the "tweens and teens" who enjoy MapleStory -- a demographic that also happens to frequent 7-Eleven. The representative calls it "the Slurpee-beverage crowd."
It's a strange world. Next thing you know we'll be buying EQ2 game-time cards at the gasoline pump!