Comment by patates
2 years ago
Maybe to stop people selling the ticket and still going to the event with a pre-printed one? Solving that would also be easy if they have a central verification system (just invalidate the ticket and issue a new one) but not if it is all p2p.
(disclaimer: I'm a complete outsider, last time I bought anything from Ticketmaster was a really long time ago).
They would need to solve that anyway in case 2 or more friends attempt to get in on the same ticket.
Not at all difficult - simply share screen a third device and display the rotating QR-code through e.g. zoom on individual phones. For additional trickery, try to split the group into joining multiple ticket scanning lines and timing the scan of the ticket to be as close as possible to eachother.