They were European based, but recently set up a USA store. I have my cards, postcards and mini cards printed by them.
Each mini moo card is different and uses my art and photography. There is plenty of room on the back for the free addition of my two shop urls and a 10% discount offer. I think that the mini Moos are better value than the Moo business cards!
When I send a package to a customer, first I take a photo of the package adorned with the business card. The photo is put into several Flickr groups, including one specifically for 'Etsy packaging'. This way, people get to see the business card.
I have, now and then stuck a small piece of sheet magnet on the reverse of the card; makes a good fridge magnet!"
I use Vistaprint.com for my business cards and invitations to shows and have been quite happy with their products. My card reflects the nature of my jewelry and designs which are very much influenced by my Greek background. Blue instead of white for the back gives the card extra pizazz.