It's very real. People nowadays increasingly use their smartphones as rolodexes. QR code is a quick way to enter contact details into one's address book. On the other hand, you can't expect everyone to have a mobile connection. Some people don't have a data plan at all, others may be saving their batteries at the moment. Often there may be no reception at the place where cards are exchanged (think of conferences that are in underground venues).

Not to mention that giving someone a business card with a link to download contact data is just wrong on many different levels. It's using a very wrong tool for the job. To put a contact file on-line you have to host it somewhere. Then the person you gave the card to has to retype the URL. URL that, like with most of the Internet, will probably be dead in six months.

Generally, the solution to the problem of digitizing the data you have physically in your hand should not involve sending packets around half of the globe.