I'm very interested in seeing the answer to this one-- I have always used a credit card to pay for my account, just because it's all automatically done between Blizzard and my bank, and I don't ever have to worry if my account is all paid up. But I'm sure there are tons of people out there, like popsixx, who play from game card to game card, buying them one after another, or hoarding them up (from gifts or elsewhere), and putting them in when necessary.
For the life of me, though, I can't guess which one would be more popular. There are definitely a lot of kids playing the game, and they'd use game cards for sure. But then again, most of the folks I play with are a little older and financially more stable, and more likely to use credit cards (or PayPal for that matter)
So which is it? Game cards or credit cards? And feel free to tell us in the comments why you do what you do-- maybe there's some huge benefit to using only game cards that I haven't noticed yet.