That was the prevailing pattern before the late 1990's, when the booming economy made agencies rush anxiously to buy time ahead of the season, fearing that prices would be higher later and supply scarcer. Now, it's going to be very slow. But this is a very concentrated industry. These are people who know each other by their first names. There are buyers who have been to every Super Bowl since the Super Bowl began.
Nobody wants to be the poster child to do the first, and worst, deal.
It's just going to take a while.