Ticketmaster
Assisting Darwin with his arguments for why government needs to regulate business i provide to you all ticketmaster.
One of the conditions to purchasing tickets through them is by giving them extensive information that they can use to advertise to you. As a business model they seem to pay large sums of money to venues so that they are the sole ticket seller. I suspect one way they offset the additional cost of locking up a venue is by forcing consumers to agree to being put on mailing list and whatnot.
Pardon mine non libertarian argument but lets gets some federal regulation up into that hizzouse.
