I'm sure they are looking for the price point at which there is still high enough demand to sell out, and high enough ticket prices to not have them sell like hotcakes.

Another aspect of this - brought up on radio - is that when you're bringing in recruits you want to show them that the program is relevant and a big deal...and you don't do that by showing them large open spaces of unsold tickets. A few in the corner won't scare anyone. But you want a full loud stadium to impress the recruits.