The QR code lets you :

• If a face-to-face contact doesn't want to give you their phone number or email, they can still retrieve your card.
• Make a public business card recoverable by a simple scan on a printed visual medium (kakemono, vehicle, flyer, etc.).
• Easily transfer the card from a computer to a smartphone.

Your contact will need to scan the QR code using an application. The iPhone camera can scan QR codes simply by holding it up to the lens, but it must be well framed.