Why are there so many magicka dlc giveaways?

Because

There's a $2 OFF coupon on amazon.

Amazon gave a "we're sorry" $2 off coupon for running out of the Deal Of The Week, but it works on anything including $2 DLC. People are using it to get free DLC and then gifting them :)

Because it's magic!

How do I get this voucher ?

Hello from Amazon. We have canceled this order because our records indicate that you have already taken advantage of this promotion with a different Amazon.com account: Order Number (#?????) This promotion is limited to one per customer to give more customers the opportunity to take advantage of the promotion. For more information on promotion restrictions, visit our Promotional Offers Help page (www.amazon.com/gp/help/customer/display.html?nodeId=?????). We thank you for choosing Amazon.com. Best regards, Account Specialist. Amazon.com

I know this isn't an Amazon.com support page, but I can't figure out how to apply the code to the order. There's no "add to cart" button, so you have to buy it with a credit card, and there's no way to apply the code before the card. Is it after entering the card info? I haven't checked that.

shut up and enjoy the giveaways