We have done this before and I'm not sure if it works or not. Business cards will unfortunately most likely end up in the trash. What we have done many times is send small gifts with the business cards. Then had other people in a group do the same thing. So say twenty people send each other these little trinkets with business cards.
We would then take these and make little gift bags and when we had a sale, whether it be online or at a craft show, we would hand them out. The customers love them. We still do it but just with our own stuff. We posted a thread here
http://handmadeartistsforum.com/forum/index.php/topic,3020.0.html in March trying to do something similar but it didn't take.
I personally think it is a good idea to do little goodie bags, it really makes the customer smile and they will remember you, whether they remember any one that you are promoting or not, who knows. But if you do an exchange like that it is a lot of work.
Business cards are easy, maybe it would be best to stick to that, who knows if you get a small return it is better than nothing right.