Sell more tickets to Prelims, Alumni & Finals. Keep costs for the venue reasonable (or nearly free, as is the case in Rochester). All of the corps involved need to make this a top priority. DCA (the admin) is a small, mostly volunteer organization. They cannot sell 10,000 tickets themselves. 35 Open Class, Class A and Alumni corps (maybe 3000 people involved?) should be able to do this, along with the marketing efforts of DCA itself.
How? Some possible easy examples....
* The member corps that sells the most tickets gets and extra 25% in their take from Finals weekend. Smaller bonuses for 2nd & 3rd, etc.
* Marching members get credit for tickets sold to help pay their dues.
* Do shared advertising, partially paid for by DCA, for all regular season shows. Every show also advertises DCA Championships. All shows should see better attendance. Win win.
* Encourage corps (with $$$) to bring young people to Finals. Younger kids from the family of corps members, bands within a reasonable distance of the Finals site, Boy Scouts, Girl Scouts, etc. Did someone really say they don't want high school band kids watching Finals? Talk about cutting off any chance for a future!
On a separate note, DCA should be (and I believe they are) working to expand its Fan Network coverage. People like to watch things at home, on their own schedule. Going to a live event is not a top priority to many people, young and old, nowadays. "But my live feed froze on me last year!" OK, that was annoying. So fix it. It can be done, and it has more potential to generate new revenue than anything else.