also: to buy and sell so as to make small quick profits ; especially : to resell at greatly increased prices
Background
"Ticket scalping" is a multi-million dollar industry. It's based on the fact that good seats for a popular show will resell for more than the face price. And they do. Some tickets for popular sporting events and concerts can sell for more than 2000% markup. Not only that, but it's entirely legal - sort of.
Legal Aspects
Ticket sales are unrestricted in all US states, except: Arkansas, Connecticut, Florida, Illinois, Kentucky, Louisiana, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, New Mexico, New York, North Carolina, Pennsylvania, Rhode Island, and South Carolina.
In these states, most brokers are required to be licensed and bonded. If a buyer or seller resides in the same regulated state where the event takes place, they are not allowed to pay more than a few dollars above face for the ticket. However, someone from a state other than where the event takes place may pay any amount for the ticket. This effectively prevents residents of regulated states from attending events near them. In most states, scalping is legal near the venue, as long as it's not on private property. It is, in effect, just soliciting.
What happens
Brokers argue that they are providing a service of obtaining premium seats. This is true, but they are catering to the rich. Undeniably, capital markets drive the economics of ticket scalping. On eBay, ticket prices are driven by an open auction system. On brokers' websites, prices fluctuate as the event nears and quantities change to meet consumer demand. The same happens when a broker is in front of the venue. Attempts to circumvent scalping tend to only help the brokers, since they are more able and willing to invest in ways to deal with the hoops set up to defeat them. Brokers are able to use ticket-buying agents, inside contacts, and simple reselling to obtain tickets and make a profit. The only way to defeat the ticket broker industry is to not buy their tickets.