Lars is one badass drummer! Not a hardcore Metallica fan, but they are some gd fantastic musicians. Not seeing the SuperB as their venue... they ain't pop!
SB is in San Fran next year, San Fran Bay Area is home to Metallica, so a fan started a petition. They won't do it though.... Metallica is NOT going to pay the NFL any money to play the HT show.
Not sure if they actually followed through on it, but they've been reported to have asked performers to pay. I read something that said the NFL asks the HT performer's to either a) pony up a percentage of future tour proceeds to them (for giving them free publicity or boosts in ticket sales, I assume), or b)make some other donation to the NFL.