I made a post on my blog about this not too long ago lol. I think that the information you put on them is paramount to the cards importance, as a designer I could easily say that the design outweighs the information, and I wish I could say that cause I'm not trying to encourage MS word designed business cards here, but if you have the best business card in the world design wise and you leave out a way to contact you, or what you can do for the client, then you wasted your time.
If you can't figure out what a person's offering, and how to get a hold of them from their business card then you throw it away, heck before I had my own business I threw away business cards that had relevant information on them so how much more likely would I have been to trash them without it? Think like a client when your ordering or designing point of contact, mailouts, and other marketing materials and you're much more likely to get business from them.
Seems like common sense when you read it but... yeah you'd be surprised.
Small Business Web & Graphic Design
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