Huge stadium rock shows, like an Oilers playoff run or The Fringe, have this great community-of-souls thing going, whether it's from the masses singing along to I Still Haven't Found What I'm Looking For, or herding into the Stadium LRT station after the show like so many PopMart T-shirt-wearing cattle.
Any time you can jam 50,000 of your neighbours into the same place at once, it's a good thing.
The repercussions go far beyond a couple of wicked shows and a whack of sated U2 fans, too.
You don't think word spreads that U2 pulled $5 million in ticket sales out of town this weekend?
Other bands see it, see that The Rolling Stones made comparable coin in 1994, and pencil in Edmonton on their tentative tour itineraries. They've got to.
Instead of being a place that bands deign to play, Edmonton's becoming a place bands would be stupid to ignore. Rumours are already starting to fly that the Stones will be back around October.
It's not just about easy cash, either. As Bono said when he stepped onto the Edmonton International Airport tarmac Friday afternoon, fans here know their music. And they're as responsive as fans anywhere.
Though there were 5,000 fewer people at Sunday's show than Saturday's, Sunday's crowd was even louder. In thanking them, Bono seemed at a loss for words. (This does not happen often.)
A little comparison is in order. Not to disparage the fine people of Las Vegas, but U2's world-tour kick-off show there was total meathead city. Fans there were way more interested in slamming Bud than singing with Bono.
Commonwealth's crowds were a perfect mix of booze-fuelled rowdiness and plain good manners. Above all, they were loud and totally into what was going down on the huge stage.
Maybe the biggest thing that made U2's weekend jaunt here so memorable is that the band took time to meet those same fans.
This, of course, is in stark contrast to The Rolling Stones, who slipped into town in 1994 under the cover of night and played a three-day game of peekaboo with the public.
We didn't have flimsy rumours of Mick Jagger jogging in the river valley. We had Bono strolling off the plane with a bunch of great quotes and a tea service in hand as the TV cameras rolled.
We didn't have a disguised Keith Richards skulking into a back entrance at the Macdonald Hotel. We had The Edge in front of the lobby doors shaking hands and signing $20 bills for fans.
This is all part of playing the game, it is true.
U2's not mounting the most extravagant tour of the decade for their health. They're touring to make money, to sell records and concert tickets, to amass hype and favourable press for future dates.
But there was still something genuine about seeing Bono at the airport, suffering through thimble-sized mosquitoes and TV reporters' inane questions so he could press the flesh with fans squeezed against the fence.
One image sticks out from the singer's whirlwind tour of the tarmac. Bono had just signed a piece of paper for a young female fan, say, 20 years old. She stood there, holding the paper and turning it over and over again, like she was afraid the signature would vanish if she held it still for just a second.
She wasn't crying, like some bad Beatlemania cliche, but rather shaking her head slightly and smiling as wide as she physically could. That's as cool as a giant lemon any day.