Ticket scalping, also known as ticket resales, is the time-honored practice of buying tickets to an event and reselling them for more than you paid for them. This is distinct from ticket brokers, businesses that buy up blocks of tickets for events for future resale, marking them up to whatever they feel the market will bear. Ticket scalping is most common for sporting and musical events. Tickets to a sold-out game or concert may be available at the right price. The stereotypical ticket scalping scenario is to go to the event venue without tickets and purchase them from a hustler in the parking lot for two or three times what the scalper paid for them.
Professional ticket scalpers often hire youngsters to wait on line for tickets to popular events to go on sale, at which point they buy as many as an individual is allowed. Ticket scalping requires a finely honed sense of the market. If the band you buy tickets for suddenly goes out of favor with the concert-going public, you might have to sell the tickets at face value or even at a loss to recoup some of your original investment.
Ticket scalping may or may not be legal in your area - local laws vary widely. In areas where ticket scalping is illegal, it is usually defined as selling tickets to an event at the venue itself, on the day of the event. Selling tickets from a storefront or online days prior to the event, at whatever markup, is usually quite legal.
There is ongoing debate about whether or not there is any reason to regulate ticket scalping. It would seem that if a person or company wants to invest the time and money to acquire blocks of tickets in advance, taking the risk that they may lose value, and people exist who are willing to pay far over the face-value for those tickets, that ticket scalping is supply and demand in its purest form. The other side of the argument is that if the ticket scalpers had not bought up all the tickets, the event would not have been sold out and attendees could have purchased face-value tickets at the event itself.
Then there are the 'accidental scalpers' - the people who purchased more tickets than they needed, not knowing friends would cancel on them, who try to recoup their costs by selling the excess tickets as they go into the event. In many areas, asking anything more than face value for your excess tickets is considered illegal ticket scalping, so make sure you know what the local laws are before you try this.