I think it would be a good addition if you add a little perk for playing every day. I enjoy this game over most card games, but just about any other game offers a little something for playing everyday.
Also I think that if you really want someone to pay for the membership it really needs some better perks. The member spot in the shop is cool and so is the reduced cost for the ladder games. But really 10% extra shards really is not that much. Gets you just a couple extra shards really. That doesn’t add up to much. Now that you took out the challenge arena, the unlock time is pointless and does nothing. Free 100 magna every week. That isn’t much. Doing the monthly membership, I would rather pay the 600 HC for 6 tries at skirmish instead of 4. Year long membership, 52 skirmishes or 5000, 5000 seems like a much better deal. Without much other perks the membership really does not seem worth the money. Just my thoughts on some things right now.