Imagine Dragons singer passed out after 'six-hour gig'
Generally speaking, if a headline artist is on stage for more than two hours most paying fans think they're getting value for money.
Bruce Springsteen will often go without a support act so he can get on earlier and this week Foo Fighter Dave Grohl spent almost three hours on stage with his Sound City Players.
But Las Vegas rockers Imagine Dragons can rival them both.
"We went to the casinos and begged them to let us play on their stages," says frontman Dan Reynolds. "They said, all right, if you play six-hour gigs - you play 50% covers, 50% originals and we'll pay you $200 (£130)."
This was typical of the gigs the foursome would play when they first got together four years ago. Most were a test of endurance.
"I wouldn't take it back - but at the time, I remember passing out on stage," smiles the singer.
"I literally passed out after a six-hour set. On the last song, I fell back on the drums. It wasn't always happy days, but it's what bonded us together as brothers."
Eventually, those marathon concerts paid off though. The band started getting booked for gigs outside their home city.
Their adventures would see them "living off peoples' couches, eating Ramen for every meal".
This all happened after Dan recruited his three bandmates (Daniel Platzman, Ben McKee and Wayne Sermon) and convinced them to move from Berklee, Boston, to join his band.
After a week they played their first gig - four years, many back-breaking shows and hard toil later - they're currently on their biggest US headlining tour to date.
Their album, Night Visions, sold 83,000 copies in its first week on sale in 2012.
It's catapulted them onto a sold out European tour and high profile TV appearances on some of America's biggest talk shows.
"We had a great experience on Jay Leno," says Ben McKee, looking cautious. "Charlie Sheen was actually the guest.
"As he came over to shake all of our hands afterwards, he leaned over and said, 'Welcome to the party, it's about to get really weird'."
Perhaps, best for them, Imagine Dragons didn't join the party. With their eyes on breaking the UK in 2013, they're far too focused.
"From the very beginning, as cheesy as it sounds, we were like those guys who had a whiteboard and we wrote down our goals," says frontman Dan.
"We're prepared for this. Our goal has always been just to make a career out of being musicians."
Night Visions is out in the UK on 1 April