Chances are, if you bought tickets from event Leviathan Ticketmaster from October 21, 1999 (DAVE, bro!) through October 19, 2011 (RADIOHEAD, bro!) you paid an Order Processing Fee. If so, you may be entitled to a taste of the recent settlement of a class action lawsuit against the company. Sure, Ticketmaster admits no wrongdoing, and the settlement only gives you a discount of $1.50 apiece for up to 17 future purchases, totaling around $11 million plus $16.5 million in legal costs. But at least they've learned their lesson: if they're going to make money off fees, they have to tell us about it. See? The system works.
The class sued Ticketmaster for not disclosing the fact that their OPFs were making them money. Well now they do, so they can charge them to their shriveled, black heart's desire. Oh and you won't be eligible for any discounts if you purchased tickets for an event at an AEG Live-operated venue (like the Best Buy Theater) because they're Ticketmaster/Live Nation's biggest competitor. Aren't you glad for those rock-solid antitrust laws? At least the minimum payout of the settlement is $11.25 million, and everything else goes to charity.
You can find out how to redeem your credits and read all of the fascinating legalese here, but if you really want to make Ticketmaster feel the pain, support your local venues that have nothing to do with them.