Another thought, and again probably one that has been thrown around or being thought of for a future update...trading cards between players.
It would be so awesome and more socially interactive if you could trade cards with other players or even buy/sell your cards between players.
I dont think this would affect people buying booster packs or decks as you can always go looking for those epic/rare cards and it would enhance the games interaction.

I know this is a pretty new game, but with the amount of growing players and people from other card games joining in it can really have a lot of future potential.

Just a thought
D