Why would anyone want to do this? It is completely zero sum. You aren't creating any wealth, even if you are making money.
For the person who has a little more money, but not enough patience or planning to login to the ticket website at 10am, actors like the commenter are creating wealth for this person.
(Okay, it likely would've gone to someone else who got there after 10 but before the customer. But now you're cheating that person out of the ticket they otherwise would've had. Still zero-sum.)
For the money, obviously.