General

A Question about Black Friday Exp Cards

Well, I've always used 2x cards right when I bought them, but for black friday I want to stock up on the cards. Therefore, I need to know do the cards activate immediately upon purchase or upon clicking them to put it in inventory? I just want some to stay in the cash shop so I could use later. I don't see any point of selling them on discount during a specific time period if they activate upon purchase. Thanks!