It's the fun things they do, like:
• Firedrills! Where all members of the band switch to the instrument on their left.
• Having their drummer Brian (who is the worst singer) sing an old pop song from the 80's.
• Playing an acoustic set of their songs with violins.
• Doing surprise "pop-up" sets in public, (like when they performed by the rear gates of the Mann Theatre or in front of a dumpster in Pittsburgh for 12 people.)
• Hiding free tickets for a scavenger hunt and giving video clues online.
• Tweeting fans to bring strange items to their concerts to dress the stage up (like potted plants and strange lamps.)
• This video . . .