[Resolved] Known Issue with the 2x EXP and Drop Coupons - 12/25/14

According to a post on Nexon forum, the one-day coupons purchased yesterday still don't work. So it must be set up such that cards purchased Dec 25 will not work, ever.
That's a rather nasty trick, intentionally disabling them but still letting people buy them without any warning. Nexon at its finest.