"Our first year on the Warped Tour was definitely a big turning point for our career. When we finished that tour, you could feel the difference," Key told Pollstar. "You could feel that more people knew ... that we'd just done a tour and played for a couple thousand people a day. It showed.
"It's exciting this year because we've been asked to be on the 'big kids' stage. It's the biggest honor we've ever received."
A deal with Lobster Records in Santa Barbara prompted Key and guitarist Ben Harper, violinist Sean Mackin, drummer Longineu Parsons and bassist Pete Mosely to leave Jacksonville for Southern California in 2000.
"I think our story is, You can do whatever your put your mind to. We made something out of nothing; we had nothing," Key said. "We were like Poison, man - packed our van up and moved to California on a whim. We didn't know what was going to happen."
In the next two years, Yellowcard released two albums and built a local following before trying a stint on the road.
"We booked a tour in May 2001 back across to Florida on our own. We did it all on the Internet with bands we knew that had been to these clubs," Key said. "It was a totally sketchy tour. Half these shows, you'd show up but nobody showed up to open the door. We toured like that for a solid year."
It was during that time Yellowcard caught the interest of Fierce Talent booking agent Corrie Christopher.
"She had heard the buzz about how hard we'd been working in Orange County and L.A. County. We sold out a show at Chain Reaction in Anaheim which is, in our world of music, a famous venue," Key said. "She asked if we'd like to work with her, and we've been with her ever since. Everything's gradually progressed from there."
However, the members of Yellowcard found themselves in a crisis a few weeks before their Capitol Records debut, Ocean Avenue, was set for release in 2003. They no longer had a manager and needed to find one fast.
"We had a guy that met us early on and offered to help us out," Key explained. "He really did a wonderful job of getting us started and helping us with money and whatnot. But, he had a life complication so we were pretty much without a manager at a really crucial time."
It was during the resulting flurry of meetings that the band hired Deborah Klein of Spivak Sobol Entertainment.
"Normally, as managers, we'll get involved with a band either right before they get signed or right after they get signed - certainly not four weeks before the record comes out," Klein told Pollstar. "I think that they were really nervous to move forward with somebody else.
"They were at a crucial junction in their career so we really had to reassure them that not only are we professionals, we know what we're doing."
Klein said the band's violin-infused rock and crafted lyrics really got her attention.
"I got the record and I was completely blown away. I hadn't seen them, and every song spoke to me. I'm not 18 years old, but it really brought me back to that time in such an immediate way," she said. "Going to see them play live for the first time was a revelation.
"I'd never seen such a response from an audience - kids singing every word, the energy onstage, every single band member with the back flips - just that connection they have with their audience."
As to what makes Yellowcard's music so appealing, Key had a simple explanation.
"It's definitely music for young people like us who want to do something better with themselves than maybe what they're expected to do, or what their environment tells them they should do," he said. "We've had a great opportunity to kind of break from the mold and do what we really had a passion for, which was making music together.
"We don't feel we're even close to what we can potentially accomplish with our music."
Yellowcard is on track to be on the road 300 days this year and won't be taking a break anytime soon. When the Warped Tour ends mid-August, the band heads overseas for club and festival dates through mid-September. A headlining tour of Australia and dates in Japan follow, with a possible break after that.
"Another thing that's so great about the guys is that they work so hard. They know what they have to do, and there's no complaining," Klein said. "They know this is the time for them. It's almost like we're just getting started, somehow."