.Cards domain for business cards, playing cards or cards of any kind
Cards are available for every occasion. There's the "Sorry to hear about your unfortunate hernia" card and the "Congratulations on your new dog" card.
There's also business cards, existing in an endless symbiotic relationship with professional networking events - both relying on the other for their continued existence. And don't forget the yellow card you get for the foul you thought the umpire didn't see during the footy game, and the postcard that says "wish you were here".
Cards are much more than just slightly-stiffer pieces of paper, and the .CARDS domain is for everyone producing or involved with cards of all kind.