Not sure if people around here know but Ticketmaster has implemented a rotating bar code system to their mobile tickets. I originally received notice from stubhub that it will be put in place soon but it looks like Ticketmaster is at least trialing it immediately.
Basically what this means is that mobile ticket screenshots will be invalid because the mobile ticket bar code will change every 60 seconds or so. The only solution is to directly transfer to the buyer through Ticketmaster.
It's not a huge burden, but certainly an extra step if you are trying to sell outside of Ticketmaster/nbatickets.com
I sold some concert tickets on stubhub about 3 months ago, sent the mobile ticket screenshots when they sold and received an email from Ticketmaster over the weekend how the rotating bar codes would be in effect for the concert which is tonight. I had to reach out to stubhub and get the buyers emails and transfer the tickets. It was a 45 minute painful call, but if i didn't make it I would have owed the money back to stubhub/ the buyer. I envision a lot of angry sellers on stubhub who missed the memo over the next few weeks.
On the flip side of that, the buyer thought they had my tickets, if they missed the new delivery method email and tried to go to the show they would have been shut out. I would have been off the hook but the buyer would have missed the show and would have not have been reimbursed.