Not directly related, but my dad used to take people to major tennis tournaments through a company he started. Many times, those who'd purchased tickets for the entire tournament didn't want to go to every match, so they'd ask him if they could sell him back individual tickets, happily taking face value. My dad, who speaks several languages, was nearly always able to move the tickets for far more than face value, and has told me many a story about getting to know professional scalpers across Europe. Every time I read a story about scalping it reminds me of him.