This is a nice get for the Grey Cup halftime show. It is certainly better than last year's joke in Saskatchewan featuring bar bands with the headliner being one-half of a band who broke up 10 years ago. That guy has trouble selling out the 1500 seat Burton Cummings Theatre. It was probably the worst halftime show (star power-wise) since the 1998 Grey Cup featuring Chris Sheppard.
Green Day is definitely bigger than Usher. Green Day was playing baseball stadiums in front of 30,000+ people during their last tour
https://en.wikipedia.org/wiki/Hella_Mega_Tour
While Usher's last tour (8 years ago!) was playing in front of crowds of 3,000 people in Glasgow and 5,000 and 6,000 people (in 20,000 seat arenas).
https://en.wikipedia.org/wiki/UR_Experience_Tour
CFL wins again!!