Arena bands - the product is the performances, the releases a means to market those performances. Or, vice versa, the performances create a space in your head in which you enjoy listening to the music more after having been to one.

What we're seeing now is similar symbiotic evolution, I hope, where the non-musical parts of the experience and the musical parts (and stage presence -is- arguably a non-musical part) feed back into each other in a positive way.