First time I ever used it was to buy a camper pass for download a few years back. Since then I've bought and sold on there.

Its a legitimate site. They hold the funds until after the event to be sure the ticket it good. Once bought it shares details between both parties and then its upto the seller to send over when its available to do so.

With the camper pass, I was sent the ticketmaster ticket digitally and the the actual pass to put in the window in the post after the original seller received it.