To dream of a business card represents resources or opportunities that are always available to you. Something or someone you can “call” or use whenever you want it. A person or situation that you feel is always available to you if you’re interested.
To dream of giving someone a business card represents your wish to be available to someone else whenever they want.
Example: A man dreamed of seeing a business card. In waking life he felt a girl was making a gesture that made him feel he could sleep with her whenever he wanted.