1. Save the digital business card onto your phone (open this page in a browser on your phone, tap and hold on the image)
  2. When you want to give your contact info, show them the QR code on your phone.
  3. When they scan it, they will see the digital business card. They can then save the image on their own phone.
  4. Since the QR code is part of the card, they can propagate it themselves on your behalf also.

Alternatively, they can also just take a picture of the card instead.