Business cards are a great way to share information.  When someone is working to draw clients, they can give them one that they can then refer to later.  The cards need to be eye catching so they can easily remember who gave it to them.

It is imperative to know the business for whom the business card is being produced.  You need to understand what they are selling and how they want to be perceived.  Once you understand that, you can tailor it to them, so they can better reach that niche of individuals who are looking for what they are selling.