Ticketmaster to Start Dynamic Ticket Pricing
MP: So now Ticketmaster, venues, and bands and their promoters are acknowledging that it was under their control all along to reduce, minimize or even completely prevent ticket scalping by simply pricing and supplying tickets according to market forces. It's only because venues, bands and their promoters have regularly under-supplied tickets at below-market prices relative to fan demand that a secondary market has flourished, with concert tickets frequently being sold above face value.
As Paul mentions in the comments below, when a band has a show that is sold-out, they can simply add more shows to increase the supply of tickets to meet the demand of their fans. Greedy ticket brokers ("scalpers") have taken all of the blame for the secondary ticket market, when the real blame should be directed towards the non-market-based, anti-fan behavior of bands and their promoters, who frequently under-supply the number of tickets their fans want to buy. They then play to sold-out shows, which creates the secondary market for tickets to those shows, but only because there is excess demand that the band failed to meet.
Update: To paraphrase/quote NormanB in the comments, "The degree to which scalpers can make money is directly related to the: a) under-pricing and b) under-supplying of the tickets in the first place." Since the: a) price and b) supply of tickets is under the direct control of the bands and their promoters/managers, they're the ones responsible for creating the secondary market.