I just received my order from Moo.com which I found through Etsy. I was intrigued by their mini cards and really liked the fact that you could add your own work to individual cards making up 50 100 or whatever. I designed my mini cards using my Etsy Shop items and some of my paintings. It was easy to put together and fun to work up the cards with sayings and things I wanted to get across. Within 7 days I received my order and Wow these are the best mini cards to date. I highly recommend using Moo.com and Etsy shop owners get a first time business card free offer which I also took advantage of and again Wow! There is a small band on the card that Moo uses to promote their services but it does not take away from your card at all.
The images on the cards are crisp and clean and the card stock is a nice heavy weight. I chose the matte finish. They also have packages of ready made designs that are fun and fit a wide variety of themes. The cards are a little more than some online printing places but the quality far outweighs any additional costs, which are minimal.
Do yourself a favor and try the promotional business cards especially artist and designer shop owners. You wont be sorry.