Clear Channel Entertainment (SFX)
http://www.cc.com/
Clear Channel Entertainment, formerly known as SFX, is a subsidiary of Clear Channel Communications, Inc. [NYSE: CCU]. Clear Channel is a global leader in the out-of home advertising industry with radio and television stations, outdoor displays and entertainment venues in 63 countries around the world. Including announced transactions, Clear Channel operates approximately 1,213 radio and 19 television stations in the United States and has equity interests in over 240 radio stations internationally. Clear Channel also operates approximately 770,000 outdoor advertising displays, including billboards, street furniture and transit panels across the world.

Ticketmaster
http://www.ticketmaster.com
Ticketmaster is the world's largest online ticketing resource. They sell tickets to more than 350,000 events each year, including professional sports, arts, family events, concerts, comedy, and more!