If the App Store requires a valid credit card, I'm surprised they don't try to do a preauth for $1.00 or something similar to validate your information. (I'm u

If the App Store requires a valid credit card, I'm surprised they don't try to do a preauth for $1.00 or something similar to validate your information. (I'm unfamiliar if this is actually the case as I don't generally use OS X / iOS.)