Many of the presales sell out in seconds and rarely are fair to players from all over the world who want to participate. Instead of doing presales in one lump sum, we perhaps should explore a staggered presale.
Lets say you are going to presale 600,000 packs, instead of allowing them to all sell out in seconds in one time zone, split them up evenly over 24 hours. For example, sell 25,000 packs at the top of every hour. This will allow paticipants from every timezone to have a chance at partipating.