Originally Posted by MiqDoloran

Since it was intended for new players they probably didn't expect to run out so quickly. If they have 1k codes each that's still a fair amount, but not nearly enough for the existing playerbase.

If Nutaku actually wanted this to draw new players then it would be a promo code only available to those without an existing account, or recently made accounts. More likely the limited quantity is intended to frustrate players into buying gatcha spins.