1. Digital tickets are purchased via mobile-friendly site or app.
2. Tickets are verified at entrance via time-sensitive QR code displayed in the app.
3. You can "resell"/transfer a ticket to another account (say, friend) via app for a small nominal fee with the cost of ticket refunded to you, but only if you provide ID (of any sort, which can be more or less reliably confirmed).
4. Ticket can be printed to obtain non-time-sensitive QR code, but only if you provide ID.