I don't think there's a chance it'd be half empty. If Ole MIss/Texas Tech in a meaningless game could pull 88,000, then Florida/Ga Tech for a chance to advance to the semi-finals of the playoffs would draw that many or more. That's a home game for somebody. You don't need to get 30,000+ from each side to travel thousands of miles, get hotels and pay for a more expensive than usual game ticket. Fans go to bowls as one off events, they will not go to multiple venues like they are following the Dead on tour. I think you could get away with a 4 team tourny with 2 bowls in which the winners face off in a championship game. But there's no way you are going to get fans to three seperate games in a multi-team playoff. It would have to be home games, which would be the end of major bowls. You can get 20,000+ fans for regular season road games without an issue. The SEC Championship game two years ago had half the Superdome filled up with Vol fans who made the trip. There is no doubt in my mind you could get 20-30 thousand fans from each side to travel to each game plus another 10-20 thousand local fans (both fans and non-fans) to come out to a game. There would also be little reason to make fans travel from Florida to Texas. Keep the games more regionalized (similarly to the regions in the basketball tournament) and the issues with getting fans out would be far less. For instance, put the hypothetical Florida/Ga Tech game in the Georgia Dome and fans would flock to it. Or if you want less of a home game, put them in the Superdome and the fans would still turn out in droves. If fans will travel in the regular season, they'll travel in the postseason as well. And if the tourney breaks down to an Ohio St./Boise St. 1st round game? Are you going to shift teams' seeding around to get close geographical matchups? Are you going to keep 20 stadiums on call in case you need to have a game there for closeness sake?