The National Performing Arts Convention is in Denver this year: http://www.performingartsconvention.org/Check it out!
Many companies offer a complimentary ticket to group leaders as a perk for organizing a group. Depending on the organization, this may be in conjunction with up to a 30% discount on the tickets. Worried about your bottom line? Worried about large numbers of comp tickets appearing on your ticket sales reports? If you offer a generous discount on the tickets for groups already, consider doing away with the comp ticket policy. Or, raise the minimum number of tickets that must be purchased in order to qualify for the comp. Perhaps your minimum group number is 10 tickets, but your minimum number to get the comp may be 50 tickets. This way, you are actually rewarding people for bringing large groups, as opposed to just for bringing a group at all.