[gcanyon]

More digital -- I haven't had business cards in ages. But even in a card case it should be possible to: 1. print cards with a unique token/whatever on each card (I get that this isn't the same as old school cards that have to be identical) 2. limit any given token to 3 uses (or similar)

[Hooray_Darakian]

I think the more practical issue is that if each business card has its own single use token then your printer is doing one copy of each card. Doable, but not how any business card company is setup today. I do get the desire for this sort of thing, but I also think most users of email treat an address as a static entity.