Do promo codes expire? I entered a promo code, signed in, and then it said the code was not recognized.
As I know, the code will expired. Some DEV said the code will expired so they give it to us. But I never have those expired. When I got a code, I will redeem it ASAP. If iTune told you that the code was not recognized, I think you got a wrong code. 1. The code may redeem not in iTune. Maybe in the game itself. 2. It is better to copy & paste the code. Capital or small letter is also accepted.
No, If someone used the code, iTune will reported it the code had been redeem and use once. That's what I saw the most.