Sustainable would be to bring in enough money to compete with what the p5 conferences are willing to spend — on coach salaries, recruiting, facilities....
UU brings in $25M+ more per year via TV, yet nets only about $10M more than BYU – and made $2M less in profit. But, with conference moneys going up each year, this gap will grow and grow.
A historic losing season, boring offenses and a weaker November schedule is what is hurting BYU's crowds (averaging only 56,250 last year).