Most ticket companies hold the money in escrow until the concert in case of cancellation. Ticketmaster bailed on this a few years ago, due to their immense amount of income. They hold enough to cover a certain percentage of their outstanding concerts, on the theory that they'd always have enough money to cover a full tour cancellation, etc. They didn't believe something could cancel all tours everywhere.
So basically we're paying for Ticketmaster's shitty business practice.