Keep in mind that the stage being in the end zone means they don't sell tickets in the sections that would be behind or directly to the side of the stage. So there looked to be about 25% of the seats unavailable, which would put capacity at around 40,000 plus whatever they allowed on the field (field was probably half full which is probably as much as the fire marshall permits, but I'm just guessing). There were a few empty seats right at the top, but not many. I suspect the show was very close to being sold out. And it was awesome. Never seen Metallica before last night, I was very impressed with how hard those boys can still rock!