Presale Issues

• A lot of concert tickets sell out before they even officially go on sale. Radio stations can claim hundreds of tickets for promotions, and guest lists can count for hundreds more. Sometimes, there are also exclusive presale offers where people with connections or the willingness to pay extra can get their tickets before the general public gets a chance to buy.
  
  

Scalpers

• Professional ticket buyers grab many of the best seats the moment that tickets go on sale. Many of them can use dozens of different computers at the same time to buy hundreds of tickets in the first few seconds of a sale. Most of them then sell the tickets to ticket reseller companies, who resell them to anyone willing to play grossly inflated prices. Other scalpers try to sell their tickets outside the concert to fans desperate to get in the door.
  
  

Speed of Sales

• Ticket sales are usually done at many different places, all opening at the same line. A major ticket vendor may allow people to buy tickets over the phone, in record stores, online and at ticket offices all at the same time. The moment that tickets go on sale, there can be hundreds of people buying. A band with a big following can sell out in minutes. Even some people waiting at the front of the ticket line or on the phone the moment the sale starts may be out of luck